Schematic eye and ophthalmologic apparatus

Abstract

To provide a schematic eye suitable as a phantom for optical coherence tomography angiography.SOLUTION: A schematic eye according to an embodiment is a phantom used to evaluate an optical coherence tomography angiography function of an ophthalmologic apparatus. The schematic eye includes a liquid storage part. In the liquid storage part, liquid with fine particles making the Brownian motion floating therein is encapsulated and stored.SELECTED DRAWING: Figure 6A

Description

[Technical field]

[0001] The present invention relates to an eye model and an ophthalmic apparatus. [Background technology]

[0002] Various imaging modalities are used in ophthalmology, one of the most well-known being optical coherence tomography (OCT), which is used for functional as well as structural imaging.

[0003] For example, OCT angiography (OCTA) is a functional imaging modality for depicting blood flow, and is used to obtain retinal and choroidal blood vessel images (see, for example, Patent Document 1). OCTA is a technology that focuses on the fact that signals from the blood flow inside blood vessels change over time, while signals from fundus tissues (structures) do not change over time, and constructs a blood vessel image by emphasizing the parts (blood flow signals) where such temporal changes exist. OCTA is also called OCT motion contrast imaging. Images constructed by OCTA are called angiography images, angiograms, motion contrast images, etc.

[0004] Ophthalmic devices capable of performing OCTA are extremely precise optical instruments, and in order to fully utilize their performance, adjustments and calibrations based on rigorous evaluations are necessary. There are various methods for evaluating ophthalmic devices, but the method of using a model eye as a phantom is widely used (for example, see Patent Documents 2 and 3, and Non-Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2015-515894 [Patent Document 2] JP 2012-110575 A [Patent Document 3] JP 2019-76181 A [Non-patent literature]

[0006] [Non-Patent Document 1] Jigesh Baxi and 7 others, "Retina-simulating phantom for optical coherence tomography", Journal of Biomedical Optics, February 2014, Vol. 19, No. 2, 021106-1~021106-8 Summary of the Invention [Problem to be solved by the invention]

[0007] However, although a conventional eye model can be used as a phantom for OCT structural imaging, it cannot be used as a phantom for OCTA.

[0008] It is also possible to construct a phantom system that mimics blood flow by flowing liquid, but this entails problems such as the need for a device to generate the liquid flow, the complexity of the model eye and system structure, and the large size of the system.

[0009] One object of the present invention is to provide a model eye suitable as a phantom for OCTA and an ophthalmic apparatus equipped with the same. [Means for solving the problem]

[0010] Some exemplary embodiments include an eye model for use in the field of ophthalmology that includes a liquid containment section that contains a liquid in which particulates are suspended.

[0011] The eye model of some exemplary embodiments includes a plurality of said liquid containments.

[0012] In some exemplary embodiments, the plurality of liquid containments contain liquids of different viscosities.

[0013] In some exemplary embodiments, the plurality of liquid containments contain liquids in which particles of different sizes are suspended.

[0014] In some exemplary embodiments, at least one of the plurality of liquid containments is disposed at an angle relative to the axial direction.

[0015] In some exemplary embodiments, at least two of the plurality of liquid containments are disposed at different inclination angles relative to the axial direction.

[0016] In some exemplary embodiments, the liquid containment portion is disposed at an angle relative to the axial direction.

[0017] Some exemplary embodiments of the eye model further include a laminate of multiple layers.

[0018] In some exemplary embodiments, the liquid containment portion is disposed within any of the layers.

[0019] In some exemplary embodiments, at least two of the layers each include the liquid containment structure.

[0020] In some exemplary embodiments, the liquid containment portion is disposed across at least two of the plurality of layers.

[0021] In some exemplary embodiments, a portion of the liquid containment portion is exposed from the laminate.

[0022] In some exemplary embodiments, the liquid containment portion is reorientable.

[0023] The eye model of some exemplary embodiments further includes a first temperature control unit for maintaining a constant temperature of the liquid.

[0024] In some exemplary embodiments, the eye model further includes a second temperature control unit for varying the temperature of the liquid.

[0025] In some exemplary embodiments, the liquid containment portion includes a tubular body in which the liquid is enclosed.

[0026] Some exemplary aspects are ophthalmic devices including a data acquisition unit for optically acquiring data of an eye and a model eye for evaluating the data acquisition unit, the model eye including a liquid storage unit that stores a liquid in which fine particles are suspended.

[0027] In some exemplary embodiments, the ophthalmic apparatus further includes an evaluation unit that generates evaluation information based on data acquired from the eye model by the data acquisition unit.

[0028] In some exemplary aspects, the data acquisition unit includes an optical system, and the ophthalmic device further includes an alignment system that aligns the optical system with a model eye installed at a predetermined position, and the evaluation unit generates the evaluation information based on data acquired from the model eye by the data acquisition unit after the alignment.

[0029] In some exemplary embodiments, the data acquisition unit acquires data from a specific portion of the model eye at least twice, and the evaluation unit generates the evaluation information based on two or more pieces of data acquired from the specific portion by the data acquisition unit. Effect of the Invention

[0030] According to some exemplary embodiments, it is possible to provide a model eye suitable as a phantom for OCTA or an ophthalmic apparatus including the model eye. [Brief description of the drawings]

[0031] [Figure 1] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Diagram 2] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 3A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 3B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 4A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 4B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Diagram 5] 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. [Figure 6A] FIG. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 6B] FIG. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 7] FIG. 1 is a schematic diagram illustrating the configuration of a laminate in an eye model according to an exemplary embodiment. [Figure 8] 1A-1C are schematic diagrams illustrating a method and configuration for creating a liquid containment section in an eye model according to an exemplary embodiment. [Figure 9] 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. [Figure 10] 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. [Figure 11] 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. [Figure 12] 1 is a schematic diagram showing the arrangement of a liquid storage section in an eye model according to an exemplary embodiment. FIG. [Figure 13A] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 13B] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 14] 1 is a schematic diagram illustrating a configuration of an ophthalmic apparatus according to an exemplary embodiment. [Figure 15] 1 is a flowchart illustrating operations that can be performed by an ophthalmic apparatus according to an exemplary embodiment. [Figure 16] 1 is an OCTA image of an eye model according to an exemplary embodiment. [Figure 17] 1 is a flow chart illustrating a method for manufacturing a laminate according to an exemplary embodiment. [Figure 18A] 1 is a schematic diagram illustrating a configuration of a model eye according to an exemplary embodiment. [Figure 18B] 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG. [Figure 18C] 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG. [Figure 19] 1 is a schematic diagram for explaining a model eye according to an exemplary embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] Some exemplary aspects of the model eye and the ophthalmic device according to the embodiment will be described. The ophthalmic device according to the exemplary aspect includes the model eye according to the exemplary aspect. Furthermore, the performance of the ophthalmic device can be evaluated using the model eye according to the exemplary aspect.

[0033] The ophthalmic apparatus according to the exemplary embodiment described below is a multifunction device in which an OCT apparatus capable of performing OCTA is combined with a fundus camera, but the ophthalmic apparatus according to the exemplary embodiment is not limited thereto and may be any ophthalmic apparatus having an OCTA function. The ophthalmic apparatus according to some exemplary embodiments has at least one of an alignment function and a performance evaluation function. The ophthalmic apparatus according to some exemplary embodiments includes a model eye for performance evaluation. On the other hand, the ophthalmic apparatus according to some exemplary embodiments does not include a model eye for performance evaluation.

[0034] The OCT device included in the ophthalmic apparatus of the exemplary embodiment described below employs spectral domain OCT, but the type of OCT applicable to the ophthalmic apparatus of the exemplary embodiment is not limited to spectral domain OCT and may be, for example, swept source OCT.

[0035] Here, spectral domain OCT is a technique in which light from a low-coherence light source is split into measurement light and reference light, the return light of the measurement light from the test object is superimposed on the reference light to generate interference light, the spectral distribution of this interference light is detected by a spectroscope, and an image is formed by performing a Fourier transform or the like on the detected spectral distribution.

[0036] In contrast, swept-source OCT is a technique in which light from a tunable light source is split into measurement light and reference light, the return light of the measurement light from the test object is superimposed on the reference light to generate interference light, this interference light is detected by a photodetector such as a balanced photodiode, and an image is formed by performing a Fourier transform or the like on the detection data collected in response to the wavelength sweep and the measurement light scan.

[0037] In this way, the spectral domain OCT is an OCT method that acquires the spectral distribution by spatial division, and the swept source OCT is an OCT method that acquires the spectral distribution by time division. Note that other OCT methods such as time domain OCT may also be used.

[0038] In this specification, unless otherwise specified, no distinction is made between "image data" and "image", which is visual information based on the image data. Furthermore, unless otherwise specified, no distinction is made between a part or tissue of the subject's eye and a corresponding part of the model eye. Furthermore, unless otherwise specified, no distinction is made between a part or tissue of the subject's eye and its image, and no distinction is made between a part of the model eye and its image.

[0039] <Configuration of Ophthalmic Device> An exemplary embodiment of an ophthalmic apparatus is shown in Fig. 1. The ophthalmic apparatus 1 includes a fundus camera unit 2, an OCT unit 100, and an arithmetic and control unit 200. The fundus camera unit 2 is provided with an optical system and a mechanism for acquiring a front image of the subject's eye E, and an optical system and a mechanism for performing OCT. The OCT unit 100 is provided with an optical system and a mechanism for performing OCT. The arithmetic and control unit 200 includes one or more processors configured to perform various processes (arithmetic, control, etc.). Furthermore, the ophthalmic apparatus 1 includes two anterior eye cameras 300 for photographing the anterior eye from two different directions.

[0040] The fundus camera unit 2 is provided with a chin rest and a forehead rest for holding the face of the subject. The chin rest and the forehead rest correspond to the face holder 450 shown in Figs. 4A and 4B. A drive mechanism and an arithmetic control circuit are housed in the base 310. An optical system is housed in a housing 320 provided on the base 310. An objective lens 22 is housed in a lens housing section 330 provided to protrude from the front surface of the housing 320.

[0041] Furthermore, the ophthalmic apparatus 1 includes a lens unit for switching the part to which OCT is applied. Specifically, the ophthalmic apparatus 1 includes an anterior segment OCT attachment 400 for applying OCT to the anterior segment. The anterior segment OCT attachment 400 may be configured similarly to the optical unit disclosed in, for example, JP 2015-160103 A.

[0042] 1, the anterior segment OCT attachment 400 can be placed between the objective lens 22 and the subject's eye E. When the anterior segment OCT attachment 400 is placed in the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the anterior segment. On the other hand, when the anterior segment OCT attachment 400 is retracted from the optical path, the ophthalmic apparatus 1 can apply an OCT scan to the posterior segment. The anterior segment OCT attachment 400 is moved manually or automatically.

[0043] In some embodiments, an OCT scan may be applied to the posterior segment when the attachment is disposed in the optical path, and an OCT scan may be applied to the anterior segment when the attachment is retracted from the optical path. In addition, the measurement site switched by the attachment is not limited to the posterior segment and the anterior segment, and may be any site of the eye. Note that the configuration for switching the site to which the OCT scan is applied is not limited to such an attachment, and it is also possible to adopt, for example, a configuration having a lens that can be moved along the optical path, or a configuration having a lens that can be inserted and removed from the optical path.

[0044] At least a portion of the functionality of the elements disclosed herein is implemented using circuitry or processing circuitry. The circuitry or processing circuitry may be a general purpose processor, a special purpose processor, an integrated circuit, a central processing unit (CPU), a graphics processing unit (GPU), an application specific integrated circuit (ASIC), a programmable logic device (e.g., a simple programmable logic device (SPLD), a complex programmable logic device (CPLD), a field programmable gate array (FPGA), a programmable logic device (PLC ... The term "circuitry", "unit", "means" or the like includes any of the above-mentioned circuitry, including a transistor and / or other circuitry, a processor, a processor array, a conventional circuitry, and any combination thereof. A processor is considered to be a processing circuitry or circuitry, including transistors and / or other circuitry. In this disclosure, a circuitry, a unit, a means, or the like is hardware that performs at least some of the disclosed functions or is hardware that is programmed to perform at least some of the disclosed functions. The hardware may be hardware disclosed herein or may be known hardware that is programmed and / or configured to perform at least some of the described functions. In the case where the hardware is a processor that can be considered to be a type of circuitry, a circuitry, a unit, a means, or the like is a combination of hardware and software, and the software is used to configure the hardware and / or the processor.

[0045] Fundus Camera Unit 2 The fundus camera unit 2 is provided with an optical system for photographing the fundus Ef (and the anterior segment) of the subject's eye E. The acquired digital image of the fundus Ef (called a fundus image, fundus photograph, etc.) is generally a front image such as an observed image or a photographed image. The observed image is obtained by capturing a moving image using near-infrared light. The photographed image is a still image captured using a flash light in the visible range.

[0046] The fundus camera unit 2 includes an illumination optical system 10 and an imaging optical system 30. The illumination optical system 10 irradiates illumination light onto the subject's eye E. The imaging optical system 30 detects return light of the illumination light irradiated onto the subject's eye E. The measurement light from the OCT unit 100 is guided to the subject's eye E through an optical path within the fundus camera unit 2. Return light of the measurement light projected onto the subject's eye E (e.g., the fundus Ef) is guided to the OCT unit 100 through the same optical path within the fundus camera unit 2.

[0047] Light (observation illumination light) output from the observation light source 11 of the illumination optical system 10 is reflected by the concave mirror 12, passes through the condenser lens 13, and passes through the visible light cut filter 14 to become near-infrared light. The observation illumination light is then focused once near the photographing light source 15, reflected by the mirror 16, and passes through the relay lens system 17, the relay lens 18, the diaphragm 19, and the relay lens system 20 to be guided to the aperture mirror 21. The observation illumination light is then reflected at the periphery (area surrounding the hole) of the aperture mirror 21, passes through the dichroic mirror 46, and is refracted by the objective lens 22 to illuminate the subject's eye E (fundus Ef). The return light of the observation illumination light from the subject's eye E is refracted by the objective lens 22, passes through the dichroic mirror 46, passes through the hole formed in the central area of ​​the aperture mirror 21, passes through the dichroic mirror 55, passes through the photographing focusing lens 31, and is reflected by the mirror 32. Furthermore, this return light passes through the half mirror 33A, is reflected by the dichroic mirror 33, and is imaged on the light receiving surface of the image sensor 35 by the imaging lens 34. The image sensor 35 detects the return light at a predetermined frame rate. The focus of the photographing optical system 30 can be adjusted to match the fundus Ef or its vicinity, and can also be adjusted to match the anterior segment or its vicinity.

[0048] The light (imaging illumination light) output from the imaging light source 15 is irradiated onto the fundus Ef through the same path as the observation illumination light. The return light of the imaging illumination light from the subject's eye E is guided to the dichroic mirror 33 through the same path as the return light of the observation illumination light, passes through the dichroic mirror 33, is reflected by a mirror 36, and is imaged by an imaging lens 37 on the light receiving surface of an image sensor 38.

[0049] A liquid crystal display (LCD) 39 displays a fixation target (fixation target image). A part of the light beam output from the LCD 39 is reflected by the half mirror 33A, reflected by the mirror 32, passes through the photographing focusing lens 31 and the dichroic mirror 55, and passes through the hole of the aperture mirror 21. The light beam that passes through the hole of the aperture mirror 21 passes through the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the fundus Ef. The fixation target is typically used to guide and fix the gaze. The direction to which the gaze of the subject's eye E is guided (and fixed), that is, the direction to which the subject's eye E is encouraged to fixate, is called the fixation position.

[0050] The fixation position can be changed by changing the display position of the fixation target image on the screen of the LCD 39. Examples of fixation positions include a fixation position for acquiring an image centered on the macula, a fixation position for acquiring an image centered on the optic disc, a fixation position for acquiring an image centered on a position between the macula and the optic disc (center of the fundus), and a fixation position for acquiring an image of a site far away from the macula (periphery of the fundus).

[0051] A graphical user interface (GUI) or the like for specifying at least one of such typical fixation positions can be provided. Also, a GUI or the like for manually moving the fixation position (display position of the fixation target) can be provided. Also, a configuration for automatically setting the fixation position can be applied.

[0052] The configuration for presenting a fixation target with a changeable fixation position to the subject's eye E is not limited to a display device such as an LCD. For example, a device (fixation matrix) in which a plurality of light-emitting units (such as light-emitting diodes) are arranged in a matrix can be used instead of a display device. In this case, the fixation position of the subject's eye E based on the fixation target can be changed by selectively turning on the plurality of light-emitting units. As another example, a fixation target with a changeable fixation position can be generated by a device having one or more movable light-emitting units.

[0053] The alignment optical system 50 generates an alignment index used for aligning the optical system with respect to the subject's eye E. Alignment light output from a light-emitting diode (LED) 51 passes through an aperture 52, an aperture 53, and a relay lens 54, is reflected by a dichroic mirror 55, passes through the hole of the aperture mirror 21, transmits through the dichroic mirror 46, and is projected onto the subject's eye E via the objective lens 22. The return light of the alignment light from the subject's eye E is guided to the image sensor 35 via the same path as the return light of the observation illumination light. Manual alignment or auto alignment can be performed based on the received light image (alignment index image).

[0054] It should be noted that the alignment method applicable to the exemplary embodiment is not limited to one that uses such an alignment indicator, and may be any known method, such as a method that uses an anterior eye camera 300, a method that uses a corneal reflection image (Purkinje image) formed by projecting a light beam onto the cornea from the front, or a method that uses an optical lever that projects a light beam onto the cornea from an oblique angle and detects the corneal reflected light in the opposite direction.

[0055] The focusing optical system 60 generates a split index used for focus adjustment of the subject's eye E. In conjunction with the movement of the photographing focusing lens 31 along the optical path (photographing optical path) of the photographing optical system 30, the focusing optical system 60 is moved along the optical path (illumination optical path) of the illumination optical system 10. The reflecting rod 67 is inserted and removed from the illumination optical path. When performing focus adjustment, the reflecting surface of the reflecting rod 67 is tilted and disposed on the illumination optical path. The focusing light output from the LED 61 passes through the relay lens 62, is split into two light beams by the split index plate 63, passes through the two-hole diaphragm 64, is reflected by the mirror 65, and is once imaged and reflected on the reflecting surface of the reflecting rod 67 by the condenser lens 66. Furthermore, the focusing light passes through the relay lens 20, is reflected by the aperture mirror 21, passes through the dichroic mirror 46, and is projected onto the subject's eye E via the objective lens 22. The return light (fundus reflection light, etc.) of the focusing light from the subject's eye E passes through the same path as the return light of the alignment light and is guided to the image sensor 35. Manual focusing or autofocusing can be performed based on the received light image (split target image).

[0056] Diopter correction lenses 70 and 71 can be selectively inserted into the photographing optical path between the aperture mirror 21 and the dichroic mirror 55. The diopter correction lens 70 is a plus lens (convex lens) for correcting strong hyperopia. The diopter correction lens 71 is a minus lens (concave lens) for correcting strong myopia.

[0057] The dichroic mirror 46 combines the optical path for fundus imaging and the optical path for OCT (measurement arm). The dichroic mirror 46 reflects light in the wavelength band used for OCT and transmits light for fundus imaging. The measurement arm is provided with a collimator lens unit 40, a retroreflector 41, a dispersion compensation member 42, an OCT focusing lens 43, an optical scanner 44, and a relay lens 45 in this order from the OCT unit 100 side.

[0058] The retroreflector 41 is movable along the optical path of the measurement light LS incident thereon, thereby changing the length of the measurement arm. The change in the measurement arm length is used, for example, to correct the optical path length according to the axial length of the eye, adjust the interference state, and so on.

[0059] The dispersion compensation member 42, together with a dispersion compensation member 113 (described later) disposed in the reference arm, acts to match the dispersion characteristics of the measurement light LS with the dispersion characteristics of the reference light LR.

[0060] The OCT focusing lens 43 is moved along the measurement arm to adjust the focus of the measurement arm. The movement of the imaging focusing lens 31, the movement of the focus optical system 60, and the movement of the OCT focusing lens 43 can be controlled in a coordinated manner.

[0061] The optical scanner 44 is disposed substantially at a position optically conjugate with the pupil of the subject's eye E. The optical scanner 44 deflects the measurement light LS guided by the measurement arm. The optical scanner 44 is, for example, a galvano scanner capable of two-dimensional scanning. Typically, the optical scanner 44 includes a one-dimensional scanner (x-scanner) for deflecting the measurement light in ±x directions and a one-dimensional scanner (y-scanner) for deflecting the measurement light in ±y directions. In this case, for example, either one of these one-dimensional scanners is disposed at a position optically conjugate with the pupil, or a position optically conjugate with the pupil is disposed between these one-dimensional scanners.

[0062] <OCT Unit 100> The exemplary OCT unit 100 shown in FIG. 2 is provided with an optical system for performing spectral domain OCT. This optical system includes an interference optical system. This interference optical system splits light from a low-coherence light source (broadband light source) into measurement light and reference light, and generates interference light by superimposing the return light of the measurement light projected onto the subject's eye E and the reference light passing through the reference light path. The spectral distribution of the interference light generated by the interference optical system is detected by a spectroscope. Data (detection signal) obtained by detecting the spectral distribution of the interference light is sent to the arithmetic and control unit 200.

[0063] The light source unit 101 outputs wideband low coherence light L0. The low coherence light L0 includes, for example, a wavelength band in the near infrared region (approximately 800 nanometers to 900 nanometers) and has a temporal coherence length of approximately several tens of micrometers. Note that the low coherence light L0 may be near infrared light having a central wavelength of, for example, approximately 1040 to 1060 nanometers that is not visible to the human eye. The light source unit 101 includes a light output device such as a superluminescent diode (SLD), an LED, or a semiconductor optical amplifier (SOA).

[0064] When swept-source OCT is employed, the light source unit includes, for example, a near-infrared tunable laser that changes the wavelength of emitted light at high speed.

[0065] Low-coherence light L0 output from light source unit 101 is guided by optical fiber 102 to polarization controller 103, where its polarization state is adjusted. The light L0 whose polarization state has been adjusted is guided by optical fiber 104 to fiber coupler 105, where it is split into measurement light LS and reference light LR. The optical path that guides the measurement light LS is called a measurement arm, etc., and the optical path that guides the reference light LR is called a reference arm, etc.

[0066] The reference light LR generated by the fiber coupler 105 is guided by the optical fiber 110 to the collimator 111, where it is converted into a parallel beam, and is guided to the retroreflector 114 via the optical path length correction member 112 and the dispersion compensation member 113. The optical path length correction member 112 acts to match the optical path length of the reference light LR with that of the measurement light LS. The dispersion compensation member 113 acts, together with the dispersion compensation member 42 arranged in the measurement arm, to match the dispersion characteristics between the reference light LR and the measurement light LS. The retroreflector 114 is movable along the optical path of the reference light LR incident thereon, thereby changing the length of the reference arm. The change in the reference arm length is used, for example, for correcting the optical path length according to the axial length of the eye, adjusting the interference state, and the like.

[0067] The reference light LR that has passed through the retroreflector 114 passes through the dispersion compensation member 113 and the optical path length correction member 112, is converted from a parallel beam to a focused beam by the collimator 116, and enters an optical fiber 117. The reference light LR that has entered the optical fiber 117 is guided to a polarization controller 118 where its polarization state is adjusted, is guided through an optical fiber 119 to an attenuator 120 where its light amount is adjusted, and is guided through an optical fiber 121 to a fiber coupler 122.

[0068] On the other hand, the measurement light LS generated by the fiber coupler 105 is guided through the optical fiber 127 to the collimator lens unit 40, where it is converted into a parallel beam, passes through the retroreflector 41, the dispersion compensation member 42, the OCT focusing lens 43, the optical scanner 44, and the relay lens 45, is reflected by the dichroic mirror 46, is refracted by the objective lens 22, and is projected onto the subject's eye E. The measurement light LS is scattered and reflected at various depth positions in the subject's eye E. The return light of the measurement light LS from the subject's eye E travels in the opposite direction through the measurement arm, is guided to the fiber coupler 105, and reaches the fiber coupler 122 via the optical fiber 128.

[0069] The fiber coupler 122 superimposes the measurement light LS incident via the optical fiber 128 and the reference light LR incident via the optical fiber 121 to generate an interference light LC.

[0070] The interference light LC generated by the fiber coupler 122 is guided to the spectrometer 130 through the optical fiber 129. The spectrometer 130 converts the incident interference light LC into a parallel beam by a collimator lens, resolves the parallel beam of interference light LC into spectral components by a diffraction grating, and projects the spectral components resolved by the diffraction grating onto an image sensor by a lens 114. This image sensor is, for example, a line sensor, and detects a plurality of spectral components of the interference light LC to generate an electrical signal (detection signal). The generated detection signal is sent to the arithmetic and control unit 200.

[0071] In addition, when swept-source OCT is adopted, interference light generated by superimposing measurement light and reference light is branched at a predetermined branching ratio (for example, 1:1) to generate a pair of interference light, and the generated pair of interference light is guided to a photodetector. The photodetector includes, for example, a balanced photodiode. The balanced photodiode includes a pair of photodetectors that detect the pair of interference light, respectively, and outputs the difference between the pair of detection signals obtained by these. The photodetector sends this output (detection signal such as a difference signal) to a data acquisition system (DAQ). A clock is supplied to the data acquisition system from the light source unit. The clock is generated in the light source unit in synchronization with the output timing of each wavelength swept within a predetermined wavelength range by the wavelength-tunable light source. For example, the light source unit branches light of each output wavelength to generate two branched lights, optically delays one of the branched lights, combines the branched lights, detects the obtained combined light, and generates a clock based on the detection signal. The data acquisition system performs sampling of the detection signal (differential signal) input from the photodetector based on the clock. The data obtained by this sampling is used for processing such as image construction.

[0072] The ophthalmic device 1 shown in Fig. 1 and Fig. 2 is provided with both an element for changing the measurement arm length (e.g., a retroreflector 41) and an element for changing the reference arm length (e.g., a retroreflector 114 or a reference mirror), but in some exemplary embodiments, only one of these elements is provided. The coherence gate position is changed by relatively changing the measurement arm length and the reference arm length (i.e., by changing the optical path length difference between the measurement arm and the reference arm). The element for changing the optical path length difference is not limited to the elements disclosed in this embodiment, and may be any element (optical member, mechanism, etc.).

[0073] <Arithmetic control unit 200> The arithmetic control unit 200 controls each part of the ophthalmic apparatus 1. The arithmetic control unit 200 also executes various calculations. For example, the arithmetic control unit 200 forms a reflection intensity profile for each A-line by performing signal processing such as Fourier transform on the spectral distribution acquired by the spectroscope 130. Furthermore, the arithmetic control unit 200 forms image data by imaging the reflection intensity profile of each A-line. The calculation processing for this purpose is similar to that of conventional spectral domain OCT.

[0074] The arithmetic control unit 200 includes, for example, a processor, a RAM (Random Access Memory), a ROM (Read Only Memory), a hard disk drive, a communication interface, etc. Various computer programs are stored in a storage device such as a hard disk drive. The arithmetic control unit 200 may also include an operation device, an input device, a display device, etc.

[0075] As shown in FIG. 3A, the user interface 240 includes a display unit 241 and an operation unit 242. The display unit 241 includes, for example, the display device 3. The operation unit 242 includes various operation devices and input devices. The user interface 240 may include a device that integrates a display function and an operation function, such as a touch panel. An ophthalmic apparatus according to some exemplary embodiments may not include at least a part of the user interface. For example, the display device and / or the operation device may be peripheral devices of the ophthalmic apparatus.

[0076] <Anterior Eye Camera 300> The anterior eye camera 300 photographs the anterior eye of the subject's eye E from two or more different directions. The anterior eye camera 300 includes an imaging element such as a CCD image sensor or a CMOS image sensor. In this embodiment, two anterior eye cameras 300 are provided on the front surface (the surface facing the subject) of the fundus camera unit 2 (see the anterior eye cameras 300A and 300B shown in FIG. 4A). As shown in FIG. 1 and FIG. 4A, the anterior eye cameras 300A and 300B are provided at positions off the optical path passing through the objective lens 22. In this disclosure, one of the anterior eye cameras 300A and 300B may be indicated by the symbol 300, and both may be indicated by the symbol 300. In addition, the anterior eye cameras that can be adopted instead of the anterior eye cameras 300A and 300B may be indicated by the symbol 300.

[0077] In this embodiment, two anterior eye cameras 300A and 300B are provided, but the number of anterior eye cameras 300 may be any number equal to or greater than 1. Considering the calculation process described below, a configuration capable of photographing the anterior eye from two different directions is sufficient (but is not limited to this). Alternatively, a movable anterior eye camera 300 may be provided to sequentially photograph the anterior eye from two or more different positions.

[0078] In this embodiment, two anterior eye cameras 300 are provided separately from the illumination optical system 10 and the photographing optical system 30, and for example, the anterior eye can be photographed using the photographing optical system 30. That is, one of the two or more anterior eye cameras 300 may be the photographing optical system 30. The anterior eye camera 300 according to this embodiment may be capable of photographing the anterior eye from two (or more) different directions.

[0079] A configuration for illuminating the anterior eye may be provided. The anterior eye illumination means includes, for example, one or more light sources. Typically, at least one light source (e.g., an infrared light source) can be provided near each of the two or more anterior eye cameras 300.

[0080] Typically, the anterior eye photographing from two or more different directions is performed substantially simultaneously. "Substantially simultaneously" means that the timing of the anterior eye photographing from two or more different directions is simultaneous, and also means that, for example, a timing difference that can ignore eye movement is intervened. By such substantially simultaneous photographing, it is possible to photograph the anterior eye from two or more different directions when the subject's eye E is in substantially the same position and orientation.

[0081] The anterior eye photographing from two or more different directions may be either video or still image photographing. In the case of video photographing, the above-mentioned substantially simultaneous anterior eye photographing can be realized, for example, by controlling the timing of starting photographing by two or more anterior eye cameras 300 to coincide, or by controlling the frame rate and the timing of acquiring each frame. On the other hand, in the case of still image photographing, the anterior eye photographing can be realized substantially simultaneously by controlling the timing of photographing by two or more anterior eye cameras 300 to coincide.

[0082] When photographing a model eye as described below, it is not necessary to perform such substantially simultaneous photographing.

[0083] <Control System> 3A and 3B show an example of the configuration of a control system (processing system) of the ophthalmologic apparatus 1. The control unit 210, the image forming unit 220, and the data processing unit 230 are provided in an arithmetic control unit 200, for example.

[0084] <Control unit 210> The control unit 210 includes a processor, and controls each unit of the ophthalmologic apparatus 1. The control unit 210 includes a main control unit 211 and a storage unit 212.

[0085] <Main control unit 211> The main controller 211 includes a processor and controls each element (including the elements shown in FIGS. 1 to 3B) of the ophthalmologic apparatus 1. The main controller 211 is realized, for example, by cooperation between hardware including a circuit and control software.

[0086] The photographing focusing lens 31 arranged in the photographing optical path and the focus optical system 60 arranged in the illumination optical path are moved integrally or in cooperation with each other by a photographing focusing drive unit (not shown) under the control of the main control unit 211. The retroreflector 41 arranged in the measurement arm is moved by a retroreflector (RR) drive unit 41A under the control of the main control unit 211. The OCT focusing lens 43 arranged in the measurement arm is moved by an OCT focusing drive unit 43A under the control of the main control unit 211. The movement of the OCT focusing lens 43 can be performed in cooperation with the movement of the photographing focusing lens 31 and the focus optical system 60. The retroreflector 114 arranged in the reference arm is moved by a retroreflector (RR) drive unit 114A under the control of the main control unit 211. Each of the mechanisms exemplified here typically includes an actuator such as a pulse motor that operates under the control of the main control unit 211. The optical scanner 44 arranged in the measurement arm operates under the control of the main control unit 211. Furthermore, the main control unit 211 can control any element included in the ophthalmic apparatus 1, such as the polarization controller 103, the polarization controller 118, the attenuator 120, various light sources, various optical elements, various devices, and various mechanisms. The main control unit 211 may also be capable of controlling any peripheral equipment (apparatus, equipment, device, etc.) connected to the ophthalmic apparatus 1, and any equipment, equipment, device, etc. accessible by the ophthalmic apparatus 1.

[0087] The moving mechanism 150, for example, moves at least the fundus camera unit 2 three-dimensionally. In a typical example, the moving mechanism 150 includes an x-stage movable in ±x directions (left and right directions), an x-moving mechanism for moving the x-stage, a y-stage movable in ±y directions (up and down directions), a y-moving mechanism for moving the y-stage, a z-stage movable in ±z directions (depth direction), and a z-moving mechanism for moving the z-stage. Each of these moving mechanisms includes an actuator such as a pulse motor that operates under the control of the main controller 211.

[0088] <Storage section 212> The storage unit 212 stores various types of data. Examples of data stored in the storage unit 212 include image data of an OCT image, image data of a fundus image, and information about the subject's eye. The information about the subject's eye includes information about the subject, such as a patient ID and name, identification information for the left eye / right eye, and electronic medical record information.

[0089] <Image forming unit 220> The image forming unit 220 forms OCT image data based on the data acquired by the spectrometer 130. The image forming unit 220 includes a processor. The image forming unit 220 is realized, for example, by cooperation between hardware including a circuit and image forming software.

[0090] The image forming unit 220 forms cross-sectional image data based on the data acquired by the spectroscope 130. This image forming process includes signal processing such as sampling (A / D conversion), noise removal (noise reduction), filtering, and fast Fourier transform (FFT), similar to conventional spectral domain OCT.

[0091] The image data formed by the image forming unit 220 is a data set including a group of image data (a group of A-scan image data) formed by imaging the reflection intensity profiles in multiple A-lines (scan lines along the z-direction) arranged in the area where the OCT scan was applied.

[0092] The image data formed by the image forming unit 220 is, for example, one or more B-scan image data, or stack data formed by embedding a plurality of B-scan image data in a single three-dimensional coordinate system. The image forming unit 220 can also perform a voxelization process on the stack data to construct volume data (voxel data). The stack data and volume data are typical examples of three-dimensional image data expressed in a three-dimensional coordinate system.

[0093] The image forming unit 220 can process the three-dimensional image data. For example, the image forming unit 220 can apply rendering to the three-dimensional image data to construct new image data. Rendering methods include volume rendering, maximum intensity projection (MIP), minimum intensity projection (MIP), surface rendering, and multiplanar reconstruction (MPR). The image forming unit 220 can also construct projection data by projecting the three-dimensional image data in the z direction (A-line direction, depth direction). The image forming unit 220 can also construct a shadowgram by projecting a part of the three-dimensional image data (three-dimensional partial image data) in the z direction. The three-dimensional partial image data is set, for example, by applying segmentation to the three-dimensional image data.

[0094] As described above, the ophthalmic device 1 of this embodiment is capable of performing OCTA. When performing OCTA, the ophthalmic device 1 repeatedly scans the same region of the fundus Ef a predetermined number of times. The image forming unit 220 constructs a motion contrast image from a data set collected by this repeated scanning. This motion contrast image is an angiographic image that emphasizes the temporal change of the interference signal caused by the blood flow of the fundus Ef and is imaged. Typically, OCTA is applied to a three-dimensional region of the fundus Ef, and image data (three-dimensional angiographic image data) that represents the three-dimensional distribution of the blood vessels of the fundus Ef is obtained.

[0095] The image forming unit 220 can construct any two-dimensional angiographic image data and / or any pseudo three-dimensional angiographic image data from the three-dimensional angiographic image data. For example, the image forming unit 220 can construct two-dimensional angiographic image data representing any cross section of the fundus Ef by applying multiplanar reconstruction to the three-dimensional angiographic image data. The image forming unit 200 can also construct en face image data from an image region (slab) corresponding to a specific tissue identified by applying segmentation to the three-dimensional angiographic image data. Typically, en face image data is constructed for various depth areas such as the superficial layer of the retina, the deep layer of the retina, and the choroid.

[0096] Data Processing Unit 230 The data processing unit 230 executes various types of data processing. For example, the data processing unit 230 can apply image processing and analysis processing to OCT image data, and can apply image processing and analysis processing to observed image data or captured image data. The data processing unit 230 includes a processor. The data processing unit 230 is realized, for example, by cooperation between hardware including a circuit and data processing software.

[0097] Next, a functional configuration of the ophthalmic device 1 realized by the elements (hardware elements, software elements) shown in Figures 1 to 3A will be described. An example of the functional configuration of the ophthalmic device 1 is shown in Figure 3B. This example provides a configuration for evaluating the ophthalmic device 1 using a model eye 500.

[0098] <Model eyes 500> The model eye 500 is a model eye according to an exemplary embodiment, and is attached to the face holder 450 via an attachment 460 in order to evaluate the performance of the ophthalmic apparatus 1. In this embodiment, the model eye 500 is placed in the same position as the subject eye E. This makes it possible to use the alignment function of the ophthalmic apparatus 1 to align the data acquisition optical system 410 with respect to the model eye 500, thereby facilitating the evaluation work, and further makes it possible to evaluate not only the quality of the data acquired by the data acquisition optical system 410, but also the quality of the alignment performed by the alignment system 420.

[0099] An exemplary configuration of the model eye 500 is shown in Fig. 5. The model eye 500 of this example includes a cornea portion 510 (cornea-equivalent lens) corresponding to the cornea, an iris portion 520 corresponding to the iris, a lens portion 550 (lens equivalent to the lens) corresponding to the crystalline lens, a vitreous portion 560 corresponding to the vitreous body, and a fundus portion 570 corresponding to the fundus. The number of elements included in the model eye 500 (e.g., the number of lenses) is arbitrary.

[0100] The iris portion 520 forms an opening 540 corresponding to a pupil. The iris portion 520 may be provided with a variable portion 530 for changing the size (opening diameter) of the opening 540. The variable portion 530 is, for example, detachable from the iris portion 520, and a plurality of members corresponding to different opening diameters are selectively applied. Alternatively, the variable portion 530 is configured to be movable with respect to the iris portion 520. The size of the opening 540 may be fixed. The vitreous portion 560 is filled with a liquid such as oil. The substance filled in the vitreous portion 560 is arbitrary, and may be, for example, any gas, any liquid, or any solid. A gas (air) typically exists in the space between the cornea portion 510 and the crystalline lens portion 550. The substance provided in the space between the cornea portion 510 and the crystalline lens portion 550 is arbitrary, and may be, for example, any gas, any liquid, or any solid.

[0101] The fundus 570 has a layered structure corresponding to the fundus of a human eye. For example, the fundus 570 has one or more layers corresponding to any tissue of the fundus of a human eye. The fundus tissues include the inner limiting membrane, nerve fiber layer, ganglion cell layer, inner plexiform layer, inner nuclear layer, outer plexiform layer, outer nuclear layer, outer limiting membrane, photoreceptor layer, retinal pigment epithelium layer, Bruch's membrane, choroid, and sclera. The thickness and refractive index of each layer of the fundus 570 may be equivalent to the thickness and refractive index of one or more corresponding tissues. The shape of the fundus 570 is not limited to a flat plate shape as shown in FIG. 5, and may be a curved shape such as a spherical shape or an elliptical shape. The fundus 570 may also have a structure corresponding to any part or tissue of a human eye. For example, the fundus 570 may have a structure corresponding to a macular region, a structure corresponding to an optic disc, a structure corresponding to a blood vessel, and the like. The fundus 570 may also have a structure corresponding to any disease, any pathological condition, or any lesion, such as a structure corresponding to age-related macular degeneration (AMD) (drusen, etc.), a structure corresponding to retinal detachment, a structure corresponding to bleeding, a structure corresponding to a tumor, or a structure corresponding to atrophy.

[0102] The parameter values ​​of the eye model 500 may be designed to be equivalent or similar to those of a human eye. The parameter values ​​of the eye model 500 may be obtained, for example, from a standard eye model or clinical data. The standard eye model may include a Gullstrand eye model, a Navarro eye model, a Liou-Brennan eye model, a Badal eye model, an Arizona eye model, an Indiana eye model, any standardized eye model, and any model eye equivalent to any of these. The eye model 500 may be designed based on an eye having a disease such as high myopia. The eye model 500 may have a structure equivalent to any disease, any pathological condition, or any lesion. For example, the eye model 500 may have a structure equivalent to any corneal disease, any lens disease, or the like. The eye model 500 may have a structure equivalent to an artificial object. For example, the eye model 500 may have an intraocular lens (IOL) or a structure equivalent thereto.

[0103] The distance between the center position of the front surface of the cornea portion 510 (the position corresponding to the corneal apex) and the front surface of the fundus portion 570 may be designed based on the axial length of the human eye. The focal length of the cornea portion 510, the lens portion 550, and the vitreous portion 560 as a whole may be designed to be equal to the focal length of the human eye. For example, the model may have a means (for example, a spacer) for changing the optical distance between the lens portion 550 and the fundus portion 570. This makes it possible to change the refractive power of the model eye 500, and for example, it is possible to perform imaging and measurement evaluation of an eye with a long axial length.

[0104] The reflectance of the front surface (surface on the cornea portion 510 side) of the iris portion 520 (variable portion 530) may be designed to be equivalent to that of the human eye. This reflectance may be, for example, the reflectance of an infrared wavelength. Similarly, the front surface of the cornea portion 510 can also be designed to be equivalent to that of the human eye. Furthermore, the model eye 500 may be designed so that the entrance pupil of the iris portion 520 (variable portion 530, opening 540) is located at a position equivalent to that of the entrance pupil of the iris of the human eye.

[0105] In order to prevent multiple reflections of the light used by the data acquisition optical system 410 (in this embodiment, the measurement light LS) and the light used by the alignment system 420 (in this embodiment, the wavelength band (e.g., infrared wavelength) detected by the anterior eye camera 300) within the model eye 500, it is possible to provide an anti-reflective coating on the lenses, etc., or to apply anti-reflective paint to the internal components.

[0106] When performing alignment using two or more anterior eye cameras 300 (cameras sensitive to infrared wavelengths) as in the ophthalmologic apparatus 1 of this embodiment, for example, the following parameter values ​​can be set. First, the entrance pupil of the opening 540 may be located at a position approximately 3.06 mm away from the cornea portion 510. The diameter of the opening 540 may be set to a value within a range of 2 to 10 mm. Furthermore, the infrared light reflectance of the iris portion 520 (variable portion 530) may be set to a value within a range of 2.0 to 2.5 percent. With such a design, it becomes possible to perform alignment with respect to the model eye 500 using the opening 540 as a reference, similar to the case of performing alignment using the pupil of a human eye as a reference.

[0107] Even when another alignment method is used, the parameter values ​​of the model eye 500 are set according to the method. For example, when alignment is performed using a corneal reflection image (Purkinje image), the radius of curvature of the cornea portion 510 (the radius of curvature of the front surface of the cornea-equivalent lens) may be set to approximately 7.7 millimeters. Similarly, when alignment is performed using an optical lever, the radius of curvature of the cornea portion 510 (the radius of curvature of the front surface of the cornea-equivalent lens) can be set to approximately 7.7 millimeters.

[0108] The fundus portion 570 is constructed using a laminate. Some exemplary embodiments of the laminate applicable to the fundus portion 570 will be described with reference to Figures 6A, 6B, 7, 8, 9, 10, 11, and 12.

[0109] FIG 6A is a side view of an exemplary embodiment stack 600, and FIG 6B is a top view of stack 600. Stack 600 includes a plurality of layers 620-1, 620-2,...,620-N, where N is an integer equal to or greater than 2. Any one of layers 620-1, 620-2,...,620-N may be referred to as 620-n (n=1, 2,...,N). Layers 620-1, 620-2,...,620-N may have, for example, different scattering properties from one another.

[0110] The shape of the layer 620-n is arbitrary, and may be formed, for example, in a flat or curved plate shape. In addition, of the multiple layers 620-1, 620-2, ..., 620-N, two adjacent layers 620-n and 620-(n+1) (n = 1, ..., N-1) are formed after one layer is hardened. This prevents the material of the layer 620-n and the material of the layer 620-(n+1) from mixing with each other, and allows each layer to exhibit its intended properties. An example of a method for manufacturing such a laminate will be described later.

[0111] The multiple layers 620-1, 620-2, ..., 620-N are formed on a substrate 610. The multiple layers 620-1, 620-2, ..., 620-N and the substrate 610 are integrally configured. That is, the lower surface of the layer 620-N located at the bottom of the multiple layers 620-1, 620-2, ..., 620-N is directly or indirectly bonded to the upper surface of the substrate 610. As an example of indirect bonding, an anti-reflection film can be disposed between the lower surface of the layer 620-N and the upper surface of the substrate 610.

[0112] The substrate 610 is typically formed of a transparent crystal. The material of the substrate 610 may be, for example, at least one of silicon dioxide (SiO2), calcium fluoride (CaF2), aluminum oxide (Al2O3), magnesium fluoride (MgF2), zinc selenide (ZnSe), germanium (Ge), calcium carbonate (CaCO3), polymethylmethacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited thereto. In some exemplary embodiments, the laminate may or may not include a substrate.

[0113] The layer 620-n has characteristics (structure, function, property) simulating some tissues (layered tissue, membranous tissue) of the human fundus. For example, the layer 620-n has characteristics (structure, function, property) corresponding to one tissue of the human fundus, one sub-tissue of one tissue, a combination of two or more sub-tissues of one tissue, a combination of two or more tissues, or a combination of two or more of these.

[0114] The layer 620-n is formed by at least a base material and particulates dispersed in the base material. In some exemplary embodiments, the base materials in the layers 620-1, 620-2, ..., 620-N have (substantially) equal refractive indices. The base material refractive index is determined according to the refractive index of the human fundus or one or more sub-tissues of the human fundus.

[0115] When the substrate refractive index is determined according to the refractive index of the human fundus, the substrate refractive index may be, for example, the standard refractive index of the human fundus as a whole or a refractive index that is approximate to the standard refractive index. Alternatively, the substrate refractive index may be a refractive index (statistical value: average value, median value, etc.) that is statistically calculated from a plurality of standard refractive indexes corresponding to a plurality of sub-tissues of the human fundus, or a refractive index that is approximate to the standard refractive index. Alternatively, the substrate refractive index may be a standard refractive index of a predetermined representative sub-tissue of the human fundus, or a refractive index that is approximate to the standard refractive index. The standard refractive index may be obtained, for example, from a standard model eye or clinical data.

[0116] When the substrate refractive index is determined according to the refractive index of one or more sub-tissues of the human fundus, the substrate refractive index may be, for example, a standard refractive index of a predetermined portion (one or more sub-tissues) of the human fundus or a refractive index that is approximate to the standard refractive index. Alternatively, the substrate refractive index may be a refractive index (statistical value: average value, median value, etc.) that is statistically calculated from two or more standard refractive indexes corresponding to two or more sub-tissues of the human fundus or a refractive index that is approximate to the standard refractive index. Alternatively, the substrate refractive index may be a standard refractive index of a predetermined representative sub-tissue of the human fundus or a refractive index that is approximate to the standard refractive index. The standard refractive index is obtained, for example, from a standard eye model or clinical data. The one or more sub-tissues of the human fundus referred to for determining the substrate refractive index may include the human retina or one or more sub-tissues of the human retina, and / or the human choroid or one or more sub-tissues of the human choroid.

[0117] For example, the refractive index of the human retina is about 1.38, and in order to achieve a substrate refractive index equivalent to that of the human fundus, it is necessary to achieve a value of about 1.40 or less. For this purpose, an organosilicon compound can be used as the substrate material. This allows the substrate refractive index to be reduced to about 1.41. In addition, by using a fluorine compound as the substrate material, the substrate refractive index can be reduced to less than 1.40.

[0118] The properties considered in the design of the multiple layers 620-1, 620-2, ..., 620-N are not limited to refractive properties (refractive index). For example, any optical properties such as transmission properties (transmittance, transmittance), diffusion properties (diffusivity, diffusion coefficient, diffusion degree) can be considered.

[0119] In addition, the scattering characteristics (scattering degree, scattering intensity, scattering coefficient) are taken into consideration in the design of the multiple layers 620-1, 620-2, ..., 620-N. As described above, the multiple layers 620-1, 620-2, ..., 620-N have different scattering characteristics from each other. The scattering characteristics of the layer 620-n are designed, adjusted, and controlled according to one or more of the layer characteristics, the substrate characteristics, the microparticle characteristics, and the combined characteristics of the substrate and the microparticles. To determine the scattering characteristics of the layer 620-n, for example, at least one of the type, size, and amount of the microparticles is referenced.

[0120] When the scattering characteristics of the layer 620-n are determined according to at least the amount of the particles, the amount of the particles can be set, for example, within a range of 0.001 weight percent to 20 weight percent as a weight percentage of the particles relative to the substrate, but is not limited thereto. In some exemplary embodiments, the amount of the particles can be set within a range of 0.04 weight percent to 4 weight percent.

[0121] When the thickness of layer 620-n is referred to in determining the scattering characteristics of layer 620-n, the layer thickness can be set in the range of 5 micrometers to 500 micrometers, but is not limited thereto. Also, the thickness of stack 600 may be in the range of 50 micrometers to 700 micrometers, but is not limited thereto.

[0122] To determine the scattering properties of layer 620-n, the material of the particles may be at least one of aluminum oxide (Al2O3), zinc oxide (ZnO), titanium oxide (TiO2), zirconium oxide (ZrO2), calcium carbonate (CaCO3), barium sulfate (BaSO4), polymethylmethacrylate resin, polyimide resin, polyethylene resin, and polycarbonate resin, but is not limited thereto.

[0123] In order to determine the scattering characteristics of the layer 620-n, the particle size can be set to be within the range of 10 nanometers to 100 micrometers, but is not limited thereto.

[0124] To determine the scattering properties of layer 620-n, the shape of the particles may be at least one of, but is not limited to, a perfect sphere, a sphere, a needle, and a star.

[0125] FIG. 7 shows an example of a schematic configuration of two layers in the laminate thus constructed. The layer 620-n1 in FIG. 7 corresponds to any one of the layers 620-1, 620-2, . . . , 620-N in FIG. 6, and the layer 620-n2 corresponds to the other layer. The refractive index of the substrate 621-n1 of the layer 620-n1 and the refractive index of the substrate 621-n2 of the layer 620-n2 are equal to each other. In addition, the two layers 620-n1 and 620-n2 have different scattering characteristics. In order to control such scattering characteristics, the particles 622-n1 in the layer 620-n1 and the particles 622-n2 in the layer 620-n2 are different from each other in at least both size and amount added.

[0126] 6A and 6B, the stack 600 of this example is provided with liquid storage sections 630-1, ..., 630-M. Here, M is an integer of 1 or more. Any one of the one or more liquid storage sections 630-1, ..., 630-M may be represented as 630-m (m = 1, ..., M). In other words, the stack 600 is provided with one or more liquid storage sections 630-1, ..., 630-M.

[0127] An example of a method for producing the liquid storage unit 630-m and an example of the configuration will be described with reference to FIG. 8. In this example, in the first step (A), a capillary (a fine tube, a tubular body) 640 that imitates blood vessels in the fundus is prepared. Both ends of the capillary 640 are open. The material of the capillary 640 may be at least one of silicon dioxide (SiO2), polymethylmethacrylate resin, polypropylene, and vinylidene chloride resin, but is not limited to these. The inner diameter of the capillary 640 (the diameter of the hollow region) may be, for example, within a range of 10 micrometers to 300 micrometers.

[0128] Although not shown, a liquid in which fine particles are suspended is prepared. The base of the liquid may be, for example, water or a water-based liquid, alcohol or an alcohol-based liquid, or glycol or a glycol-based liquid, but is not limited thereto. The viscosity of the liquid may be, for example, within a range of 0.5 mPascal seconds to 100 mPascal seconds, but is not limited thereto. The material of the fine particles added to the liquid may be, for example, a metal complex (copper complex, iron complex, etc.), but is not limited thereto. The concentration of the fine particles added to the liquid may be, for example, within a range of 0.01 weight percent to 5.00 weight percent, but is not limited thereto.

[0129] In the next step (B), liquid 641 in which the particles are suspended is injected into capillary 640. This causes the hollow region of capillary 640 to be filled with liquid 641 in which the particles are suspended.

[0130] In the next step (C), both ends (openings) of the capillary 640, whose hollow region is filled with the liquid 641 in which the fine particles are suspended, are closed. The method for closing the openings is arbitrary, and for example, welding is used. The locations of both ends of the capillary 640 thus closed are indicated by symbols 642 and 643.

[0131] In the next step (D), a cover 644 for covering the blocked portion 642 at the first end of the capillary 640 and a cover 645 for covering the blocked portion 642 at the second end are attached.

[0132] In the final step (E), adhesive 646 is filled into the gap between blocked portion 642 of capillary 640 and cover 644, and adhesive 647 is filled into the gap between blocked portion 643 and cover 645. By hardening adhesives 646 and 647, liquid 641 in which particles are suspended is completely sealed inside capillary 640. As a result, liquid storage section 630-m in which liquid 641 in which particles are suspended is stored is obtained.

[0133] When multiple liquid storage sections 630-1, ..., 630-M (M is an integer of 2 or more) are provided, these liquid storage sections 630-1, ..., 630-M may have different features (configurations, functions, properties) from each other. For example, the multiple liquid storage sections 630-1, ..., 630-M may have different forms from each other. Typically, the multiple liquid storage sections 630-1, ..., 630-M may have different shapes and / or different dimensions (length, thickness, diameter, etc.) from each other. In addition, the multiple liquid storage sections 630-1, ..., 630-M may be formed from different materials from each other.

[0134] The liquid storage units 630-1, ..., 630-M may be configured so that the moving speeds of the particles suspended in the stored liquid are different from each other. For this purpose, any parameter related to the liquid and / or any parameter related to the particles may be considered. The parameter considered may be any parameter that affects the Brownian motion of the particles in the liquid. For example, the moving speed of the particles suspended in the liquid can be controlled by adjusting any parameter among the viscosity of the liquid, the temperature of the liquid, and the form (shape, size) of the particles. That is, the liquid storage units 630-1, ..., 630-M may store liquids of different viscosities, may store liquids of different temperatures, and may store liquids in which particles of different sizes are suspended.

[0135] For example, as shown in FIG. 9(A), the liquid storage section 630-m may be disposed at an incline with respect to a predetermined axial direction 650. The axial direction 650 may be defined by the model eye (laminate 600A, 600B) and / or the evaluation method. For example, the axial direction 650 may be a direction corresponding to the ocular axis in the model eye (laminate 600A, 600B) having a structure simulating an eye. Alternatively, the axial direction 650 may be a direction in which a plurality of layers in the laminate (600A, 600B) are laminated (i.e., the thickness direction, depth direction, etc. of the laminate). Alternatively, the axial direction 650 may be an axial direction used in OCT (i.e., the z direction, the A-scan direction, the measurement light incidence direction, etc.). By tilting in this way, it becomes possible to obtain blood flow parameters (blood flow velocity, blood flow amount, etc.) in addition to the presence or absence of blood flow. That is, it becomes possible to evaluate the amount of Doppler shift caused by the direction of blood flow.

[0136] When a plurality of liquid storage units 630-1, ..., 630-M (M is an integer of 2 or more) are provided, at least one of these liquid storage units 630-1, ..., 630-M may be arranged at an inclination with respect to the axial direction 650. Furthermore, at least two of these liquid storage units 630-1, ..., 630-M may be arranged at different inclination angles with respect to the axial direction 650. For example, as shown in FIG. 9(B), both of the two liquid storage units 630-m1 and 630-m2 may be inclined with respect to the axial direction 650, and the inclination angle of the liquid storage unit 630-m1 with respect to the axial direction 650 and the inclination angle of the liquid storage unit 630-m2 with respect to the axial direction 650 may be different from each other. This makes it possible to obtain information that indicates the relationship between the inclination angle and the blood flow parameter. For example, it is possible to obtain the blood flow parameter for each of the different inclination angles, and it is possible to perform an evaluation according to the obtained information. It is also possible to obtain the change or sensitivity of the blood flow parameter according to the change in the inclination angle, and it is possible to perform an evaluation according to the change in the blood flow parameter.

[0137] In the case where a model eye including a laminated body made of a plurality of layers is adopted, such as the model eye 500 of this example, the arrangement relationship between the plurality of layers and the liquid storage unit may be arbitrary. For example, as shown in FIG. 6A, a liquid storage unit may be arranged between layers. Also, as shown in FIG. 10(A), a liquid storage unit 630-m may be arranged inside any layer 620-n of the laminated body. Also, as shown in FIG. 10(B), a liquid storage unit 630-m may be arranged inside layer 620-n of the laminated body, and a liquid storage unit 630-(m+1) may be arranged inside layer 620-(n+1). Note that the number of layers in which the liquid storage unit is provided is arbitrary, and the two layers in which the liquid storage unit is provided may or may not be adjacent to each other. As shown in FIG. 10(C), a single liquid storage unit 630-m may be arranged across two layers 620-n and 620-(n+1) of the laminated body. The liquid storage unit may be arranged across three or more layers. Another example in which a single liquid storage unit 630-m is arranged across two layers 620-n and 620-(n+1) is shown in FIG. 10(D). In this example, the liquid storage unit 630-m is arranged at an angle to a predetermined axial direction. These are some examples of model eyes that mimic the distribution of blood vessels in the fundus.

[0138] In order to easily determine the part of the model eye (fundus, laminate) to which OCT scanning for performance evaluation of the ophthalmologic device 1 is applied, a configuration can be adopted that allows the liquid storage section or its position to be recognized from the outside.

[0139] In some exemplary embodiments, it is possible to adopt a configuration in which a part of the liquid storage unit is exposed from the laminate. FIG. 11 is a top view of a laminate 600C having such a configuration. A central portion 630a of the liquid storage unit 630 provided in the laminate 600C is embedded in the laminate 600C, and both ends 630b and 630c are exposed from the laminate 600C. The user can grasp the position of the liquid storage unit 630 by referring to the exposed both ends 630b and 630c. This allows the user to determine the range to which the OCT scan for performance evaluation is applied and the orientation in which the model eye is placed.

[0140] The embodiment that can be adopted to obtain the same effect is not limited to this. For example, a mark indicating the position of the liquid storage unit embedded in the laminate can be attached to the outer surface of the model eye, the outer surface of the fundus, and the outer surface of the laminate. Alternatively, the laminate may be formed using a transparent material.

[0141] The orientation of the liquid storage unit when performing an OCT scan for performance evaluation of the ophthalmologic device 1 may be arbitrary. In addition, it is possible to configure one or more of the model eye, the fundus, and the laminate to be movable and / or variable, or to configure one or more of a part of the model eye, a part of the fundus, and a part of the laminate to be movable and / or variable. For example, as shown in Fig. 12(A) and Fig. 12(B), the laminate 600D can be configured to be rotatable around a predetermined axis, thereby making it possible to change the orientation of the liquid storage unit 630D.

[0142] In some exemplary embodiments, a liquid having a high viscosity such that Brownian motion of particles does not substantially occur may be enclosed in the capillary. In the evaluation of OCTA function, the purpose is to obtain a signal (motion signal) representing the motion of particles in liquid. According to this embodiment, a signal (reference signal) for a state in which the motion of particles is substantially zero is obtained, and the motion signal can be analyzed using this reference signal. For example, the motion signal can be corrected by using the reference signal as an offset. In addition, noise of the motion signal can be removed by treating the reference signal as a signal representing inherent noise generated from a group of elements for OCTA (optical system, processing system, etc.). In addition, the reference signal can be used for evaluation and calibration of a model eye for acquiring a motion signal (i.e., a model eye including a capillary filled with a liquid having a low viscosity in which Brownian motion of particles occurs). For example, it is possible to refer to the difference (difference, ratio, etc.) between the reference signal and the motion signal in order to adjust the parameters (temperature, etc.) of the model eye for acquiring a motion signal.

[0143] <Face holder 450, attachment 460> The face holder 450 is a member that holds the subject's face to fix the position of the subject's eye E. A chin rest and a forehead rest are provided in a typical ophthalmic device (see, for example, Japanese Patent Application Laid-Open No. 2010-200905 and Japanese Patent Application Laid-Open No. 2015-139527). The subject's chin is placed on the chin rest. The subject's forehead is placed (comes into contact) with the forehead rest.

[0144] The attachment 460 is a member for mounting the model eye 500 to the ophthalmic device 1. Typically, the attachment 460 is interposed between the model eye 500 and the ophthalmic device 1. In some exemplary embodiments, the model eye 500 and the attachment 460 may be integrally configured, but in this embodiment, the model eye 500 is detachably attached to the attachment 460. For example, the model eye 500 is attached to the attachment 460, and the attachment 460 is attached to the face holder 450. In other words, the model eye 500 is indirectly attached to the ophthalmic device 1 via the attachment 460.

[0145] The location of the ophthalmic device 1 where the model eye 500 (attachment 460) is attached is not limited to the face holder 450. For example, it is possible to adopt a configuration in which the model eye 500 is attached to the outer surface of a housing that houses the data acquisition optical system 410, or a configuration in which the model eye 500 is built into the housing. When the model eye 500 is built into the housing, the model eye 500 may be configured to be insertable into the optical path of the data acquisition optical system 410, or may be arranged in an optical path branched from the optical path of the data acquisition optical system 410. In the latter case, for example, when a performance evaluation is performed using the model eye 500, a total reflection mirror or a beam splitter is inserted into the optical path of the data acquisition optical system 410, and light (e.g., measurement light LS) from the data acquisition optical system 410 is guided to the model eye 500 via the branched optical path.

[0146] Data Acquisition Optical System 410 The data acquisition optical system 410 is an optical system for acquiring data of the subject's eye E. When evaluating the ophthalmic apparatus 1, the data acquisition optical system 410 acquires data from the model eye 500 in the same manner as acquiring data from the subject's eye E. For example, the ophthalmic apparatus 1 of this embodiment can acquire data from the fundus 570 by applying an OCT scan to the model eye 500. In addition, the ophthalmic apparatus 1 of this embodiment can photograph the fundus 570 of the model eye 500 using the fundus camera unit 2.

[0147] <Alignment System 420> The alignment system 420 is configured to align the data acquisition optical system 410 with the model eye 500 placed at a predetermined position.

[0148] In this embodiment, the alignment system 420 includes two anterior eye cameras 300, a processing unit 430, and a moving mechanism 150. As described above, the two anterior eye cameras 300 include imaging elements sensitive to infrared wavelengths, and are configured to capture images of the model eye 500 installed at a predetermined position from two different directions. The moving mechanism 150 is configured to move the data acquisition optical system 410.

[0149] Processing section 430 The processing unit 430 controls the moving mechanism 150 based on two or more images of the model eye 500 acquired by the two anterior eye cameras 300 .

[0150] The processing unit 430 is configured to execute the processing described in, for example, Japanese Patent Application Laid-Open No. 2013-248376 filed by the present applicant. More specifically, the processing unit 430 first analyzes each of the two images of the model eye 500 captured by the two anterior eye cameras 300 to identify the pupil region in each image.

[0151] Next, the processing unit 430 calculates the amount of three-dimensional movement of the data acquisition optical system 410 based on the two pupil regions identified from the two images. Trigonometry is used for this calculation.

[0152] Furthermore, the processing unit 430 controls the moving mechanism 150 based on the calculated three-dimensional movement amount. More specifically, the processing unit 430 controls the moving mechanism 150 so as to move the data acquisition optical system 410 by the calculated three-dimensional movement amount (movement amount in the x direction, movement amount in the y direction, and movement amount in the z direction).

[0153] For details of the processing performed by the processing unit 430, please refer to a series of documents by the present applicant related to inventions using two or more anterior eye cameras, such as Japanese Patent Application Laid-Open No. 2013-248376 and Japanese Patent Application Laid-Open No. 2014-113385. The processing unit 430 is realized by, for example, the main control unit 211 and the data processing unit 230.

[0154] The ophthalmologic apparatus 1 of this embodiment may use the alignment optical system 50 to align the data acquisition optical system 410 with the model eye 500. In this case, auto-alignment using an alignment index (described above) is applied to the model eye 500.

[0155] Some exemplary embodiments of the ophthalmic apparatus may be capable of performing XY alignment and / or Z alignment described in Japanese Patent Application Laid-Open No. 2018-164616 filed by the present applicant. XY alignment is an alignment method using a corneal reflection image (Purkinje image), and Z alignment is an alignment method using an optical lever.

[0156] When applying a technique using a corneal reflection image (Purkinje image) to the alignment of the data acquisition optical system 410 with respect to the model eye 500, for example, the configuration shown in Fig. 13A can be adopted instead of the configuration shown in Fig. 3B. In the configuration example shown in Fig. 13A, the alignment system 420 shown in Fig. 3B is replaced with an alignment system 420A. Among the elements shown in Fig. 13A, the same elements as those in Fig. 3B are indicated by the same reference numerals, and unless otherwise specified, the description of those elements will not be repeated.

[0157] The model eye 500 of this example includes at least a cornea portion (510) corresponding to the cornea, and the radius of curvature of this cornea portion is set to approximately 7.7 mm.

[0158] The alignment system 420A includes a projection section 421A, an imaging section 422A, a processing section 430A, and a moving mechanism 150.

[0159] The projection unit 421A projects a light beam onto the model eye 500. In particular, the projection unit 421A projects a light beam onto the model eye 500 from the front. Typically, the projection unit 421A is configured to project a parallel light beam onto the model eye 500 through a part of the optical path of the data acquisition optical system 410. As a result, a bright spot image (corneal reflection image, Purkinje image) is formed on the cornea of ​​the model eye 500.

[0160] The photographing unit 422A photographs the model eye 500 in a state where a light beam is projected by the projection unit 421A. A corneal reflection image is depicted in the image of the model eye 500 obtained by the photographing unit 422A. The image of the model eye 500 obtained by the photographing unit 422A is input to the processing unit 430A. The photographing unit 422A is an area sensor in which multiple light receiving elements (photoelectric conversion elements) are two-dimensionally arranged.

[0161] The processing unit 430A analyzes the image of the model eye 500 acquired by the imaging unit 422A to identify the corneal reflection image. This analysis includes, for example, image processing based on changes in luminance values ​​(for example, edge detection).

[0162] Furthermore, the processing unit 430A controls the moving mechanism 150 based on the corneal reflection image identified from the image of the model eye 500. For example, the processing unit 430A calculates the deviation of the corneal reflection image from a predetermined reference position (for example, a position corresponding to the optical axis of the data acquisition optical system 410), and controls the moving mechanism 150 to cancel this deviation (so that the corneal reflection image is located at the reference position). This makes it possible to guide the optical axis of the data acquisition optical system 410 to the apex position of the cornea of ​​the model eye 500.

[0163] For details of the processing performed by the processing unit 430A, see, for example, Japanese Patent Application Publication No. 2018-164616 and Japanese Patent Application Publication No. 10-024019. The processing unit 430A is realized by, for example, the main control unit 211 and the data processing unit 230.

[0164] When applying the technique using an optical lever to the alignment of the data acquisition optical system 410 with respect to the model eye 500, for example, the configuration shown in Fig. 13B can be adopted instead of the configuration shown in Fig. 3B. In the configuration example shown in Fig. 13B, the alignment system 420 shown in Fig. 3B is replaced with an alignment system 420B. Among the elements shown in Fig. 13B, the same elements as those in Fig. 3B are indicated by the same reference numerals, and unless otherwise specified, the description of those elements will not be repeated.

[0165] The model eye 500 of this example includes at least a cornea portion (510) corresponding to the cornea, and the radius of curvature of this cornea portion is set to approximately 7.7 mm.

[0166] The alignment system 420B includes a projection section 421B, an imaging section 422B, a processing section 430B, and a moving mechanism 150.

[0167] The projection unit 421B projects a light beam onto the model eye 500. In particular, the projection unit 421B projects a light beam obliquely onto the model eye 500. Typically, the projection unit 421B is configured to project a parallel light beam onto the model eye 500 from a position outside the optical path of the data acquisition optical system 410. As a result, the light beam projected onto the cornea of ​​the model eye 500 is reflected by the surface of the cornea.

[0168] The photographing unit 422B is disposed in a direction approximately symmetrical to the direction of projection of the light beam by the projection unit 421B with respect to the optical axis of the data acquisition optical system 410. Typically, the projection unit 421B and the photographing unit 422B are disposed in positions approximately symmetrical to each other with respect to the optical axis of the data acquisition optical system 410. Typically, the photographing unit 422B is a line sensor in which a plurality of light receiving elements are arranged one-dimensionally. Note that the photographing unit 422B may be an area sensor in which a plurality of light receiving elements are arranged two-dimensionally. When the distance between the model eye 500 and the data acquisition optical system 410 is within a predetermined range, the reflected light (corneal reflected light) of the light beam emitted from the projection unit 421B by the cornea is detected by the photographing unit 422B. When the corneal reflected light is not detected by the photographing unit 422B, the image obtained by the photographing unit 422B is an all-black image. On the other hand, when the corneal reflected light is detected by the image capturing section 422B, a bright spot image is included in the image obtained by the image capturing section 422B. The image obtained by the image capturing section 422B is input to the processing section 430B.

[0169] The processing unit 430B analyzes the image acquired by the photographing unit 422B to determine the presence or absence of a bright spot image, and if there is no bright spot image, sends a predetermined control signal to the moving mechanism 150. On the other hand, if there is a bright spot image, the processing unit 430B identifies the position of the bright spot image and obtains the deviation of the position of the bright spot image from a predetermined reference position. In other words, the processing unit 430B identifies the address of the light receiving element that detected the corneal reflected light among the multiple light receiving elements of the photographing unit 422B, and obtains the deviation between the address of this light receiving element and a predetermined reference address.

[0170] Furthermore, the processing unit 430B controls the moving mechanism 150 based on the deviation thus identified. For example, the processing unit 430B controls the moving mechanism 150 so as to cancel this deviation (so that the corneal reflected light is detected by the light receiving element at the reference address). This makes it possible to guide the distance between the model eye 500 and the data acquisition optical system 410 to a predetermined working distance.

[0171] For details of the processing performed by the processing unit 430B, see, for example, Japanese Patent Application Publication No. 2018-164616 and Japanese Patent Application Publication No. 2015-146859. The processing unit 430B is realized by, for example, the main control unit 211 and the data processing unit 230.

[0172] <Evaluation Section 440> For example, after alignment is performed by the alignment system 420 (420A, 420B), the data acquisition optical system 410 acquires data of the model eye 500. For example, the ophthalmologic apparatus 1 aligns the data acquisition optical system 410 with respect to the model eye 500 by the alignment system 420, and then applies an OCT scan to the model eye 500 by the data acquisition optical system 410. This OCT scan is typically a scan for OCTA, and applies scans to a specific portion of the model eye 500 a predetermined number of times.

[0173] The evaluation unit 440 generates evaluation information based on data of the model eye 500 acquired after alignment. For example, the evaluation unit 440 may be configured to generate data quality evaluation information indicating the quality of data acquired by the data acquisition optical system 410. The evaluation unit 440 may also be configured to generate alignment quality evaluation information indicating the quality of alignment performed by the alignment system.

[0174] When generating data quality evaluation information, the evaluation unit 440 executes a predetermined data quality evaluation process. For example, as described above, when the fundus 570 of the model eye 500 has a layered structure corresponding to the fundus of a human eye, the ophthalmologic apparatus 1 applies an OCT scan to the fundus 570 by the data acquisition optical system 410. The image forming unit 220 forms an image of the fundus 570 from the OCT data acquired by the data acquisition optical system 410. The evaluation unit 440, for example, compares the formed image of the fundus 570 with a predetermined evaluation image. The evaluation image is, for example, an image of the fundus 570 with high data quality. The evaluation unit 440 can generate data quality evaluation information based on the result of the comparison between the image of the fundus 570 and the evaluation image.

[0175] In this embodiment, the evaluation unit 440 is configured to perform quality evaluation of the OCTA data. The ophthalmic device 1 applies an OCT scan to a region of the fundus 570 including at least a part of at least one of the liquid storage units 630-1, . . . , 630-M by the data acquisition optical system 410 a predetermined number of times. For example, the ophthalmic device 1 may repeatedly apply an OCT scan to the entire fundus 570. The image forming unit 220 constructs a motion contrast image from a data set collected by the repeated OCT scan. This motion contrast image is a simulated angiographic image that emphasizes and visualizes a temporal change in an interference signal caused by the Brownian motion of particles in the liquid storage unit 630-m. This simulated angiographic image is three-dimensional image data, and the image forming unit 220 can construct any two-dimensional image data and / or any three-dimensional image data from this three-dimensional image data as described above. The evaluation section 440 can generate quality evaluation information of the OCTA data, for example, by comparing the constructed image of the fundus 570 (OCTA image) with a predetermined evaluation image.

[0176] As another example of generating the data quality evaluation information, the evaluation unit 440 can obtain the value of a predetermined evaluation parameter representing the data quality by analyzing the data acquired by the data acquisition optical system 410. The evaluation parameter may be, for example, an image quality evaluation parameter such as contrast or S / N ratio. The evaluation parameter may also be, for example, a measurement quality evaluation parameter such as a measurement accuracy parameter or a measurement precision parameter.

[0177] When generating the alignment quality evaluation information, the evaluation unit 440 executes a predetermined alignment quality evaluation process. For example, the evaluation unit 440 can evaluate the alignment quality based on the time required for alignment, the processing contents, and the results. The evaluation unit 440 can also evaluate the alignment error with respect to the liquid storage unit 630-m as the alignment target.

[0178] In some exemplary embodiments, the evaluation unit 440 can generate the alignment quality evaluation information based on the length of time (alignment time) from the start of alignment to reaching a suitable alignment state (e.g., a state in which the alignment error is within a predetermined range). For example, the evaluation unit 440 can compare the alignment time with a predetermined threshold, and evaluate the alignment time as "low quality" if it exceeds the threshold, and evaluate the alignment time as "high quality" if it is equal to or less than the threshold. Alternatively, the evaluation unit 440 can be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the alignment time belongs to, and generate the alignment quality evaluation information based on the range to which the alignment time belongs.

[0179] In some exemplary embodiments, the evaluation unit 440 can generate alignment quality evaluation information based on the content of the processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can generate alignment quality evaluation information based on the number of repetitions of the alignment operation performed from the start of alignment until a suitable alignment state is reached. The alignment operation is, for example, the number of times the processing unit 430 (430A, 430B) processes an image from the anterior eye camera 300. For example, the evaluation unit 440 can compare the number of repetitions of the alignment operation with a predetermined threshold, and evaluate the number of repetitions as "low quality" if the number of repetitions exceeds the threshold, and evaluate the number of repetitions as "high quality" if the number of repetitions is equal to or less than the threshold. Alternatively, the evaluation unit 440 may be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the number of repetitions belongs to, and generate alignment quality evaluation information based on the range to which the number of repetitions belongs.

[0180] In some exemplary embodiments, the evaluation unit 440 can generate the alignment quality evaluation information based on the result of the processing performed by the alignment system 420 (420A, 420B). For example, the evaluation unit 440 can determine an alignment state (e.g., an alignment error) reached by the alignment system 420 performing an alignment operation for a predetermined time, and generate the alignment quality evaluation information based on the alignment error. For example, the evaluation unit 440 can compare the alignment error with a predetermined threshold, and evaluate the alignment error as "low quality" if the alignment error exceeds the threshold, and evaluate the alignment error as "high quality" if the alignment error is equal to or less than the threshold. Alternatively, the evaluation unit 440 may be configured to determine which of a plurality of predetermined ranges (high quality range, acceptable range, poor range) the alignment error belongs to, and generate the alignment quality evaluation information based on the range to which the alignment error belongs.

[0181] As described above, temperature is a parameter that affects the Brownian motion of particles in liquid. Here, an embodiment in which the temperature of the liquid can be controlled will be described with reference to FIG. 14. The configuration shown in FIG. 14 is obtained by adding a temperature control unit 470 to the configuration shown in FIG. 3B. Note that the configuration capable of executing liquid temperature control is not limited to this, and for example, the temperature control unit 470 or an element equivalent thereto may be added to any of the configuration equivalent to the configuration shown in FIG. 3B, the configuration shown in FIG. 13A or an equivalent thereto, the configuration shown in FIG. 13B or an equivalent thereto, and any other embodiment of the configuration.

[0182] In the first embodiment, the temperature control unit 470 is configured to keep the temperature of the liquid stored in the liquid storage unit 630-m constant. For example, the temperature control unit 470 in this embodiment includes a first means for changing the amount of thermal energy of the liquid, a second means for measuring the temperature of the liquid, and a third means for controlling the first means so that the temperature measured by the second means becomes a predetermined value. Each means may have any known configuration. For example, the first means may be a means for outputting hot air and / or cold air, the second means may be a thermistor or a thermocouple sensor, and the third means may be a processor. According to this embodiment, the temperature of the liquid stored in the liquid storage unit 630-m can be kept almost constant, so that the state of Brownian motion of the particles floating in the liquid (such as the moving speed of the particles) can be stabilized. This makes it possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic device 1.

[0183] In the second embodiment, the temperature control unit 470 is configured to change the temperature of the liquid stored in the liquid storage unit 630-m. The temperature control unit 470 in this embodiment may be the same as that in the first embodiment. According to this embodiment, the temperature of the liquid stored in the liquid storage unit 630-m can be changed to a desired temperature, so that the state of Brownian motion of the particles floating in the liquid (such as the moving speed of the particles) can be brought to a desired state. This makes it possible to improve the accuracy, precision, reproducibility, etc. of the performance evaluation of the ophthalmic device 1.

[0184] <Operation> An example of the operation of the ophthalmic apparatus 1 according to this embodiment will be described below. An example of the operation of the ophthalmic apparatus 1 is shown in FIG.

[0185] First, the model eye 500 is placed at a predetermined position for evaluating the ophthalmic device 1 (S1). In this embodiment, for example, the two model eyes 500 (left model eye, right model eye) are attached to the face holder 450 using the attachment 460. Note that it may be possible to directly attach the model eye 500 to a chin rest, directly or indirectly attach the model eye 500 to a forehead rest, or directly or indirectly attach the model eye 500 to another location on the ophthalmic device 1.

[0186] After the eye model 500 is attached to the ophthalmic apparatus 1, the ophthalmic apparatus 1 starts alignment of the eye model 500 (S2). This alignment is performed using, for example, any of the alignment system 420 in Fig. 3B, the alignment system 420A in Fig. 13A, and the alignment system 420B in Fig. 13B.

[0187] The alignment is performed, for example, until a suitable alignment state is achieved, or for a predetermined time, or until a predetermined number of iterations of the alignment operation are reached. Note that the suitable alignment state referred to here is a state suitable for evaluating OCTA functionality, typically a state in which an OCT scan is applied to at least one liquid containment portion 630-m.

[0188] When the alignment is completed (S3), the ophthalmologic apparatus 1 applies an OCT scan to the model eye 500 (S4). This OCT scan is an OCT scan of the fundus portion 570, and is a repetitive OCT scan for OCTA. Note that an OCT scan of a portion corresponding to the anterior segment (one or more of the cornea portion 510, the iris portion 520, the variable portion 530, the aperture 540, and the lens portion 550) may be (additionally) performed. Also, a scan for evaluation of OCT function for structural imaging and / or a scan for evaluation of OCT function for functional imaging other than OCTA may be (additionally) performed.

[0189] The ophthalmic apparatus 1 generates an OCTA image from the data set collected in the repetitive OCT scan in step S4 by the image generating unit 220 (S5).

[0190] Furthermore, the ophthalmic apparatus 1 generates evaluation information based on the OCTA image formed in step S5 by the evaluation unit 440 (S6). For example, the ophthalmic apparatus 1 can generate data quality evaluation information regarding the OCTA function by the evaluation unit 440. Also, the ophthalmic apparatus 1 can generate alignment quality evaluation information based on data obtained regarding the alignment in step S3 by the evaluation unit 440.

[0191] The evaluation information generated in step S6 is displayed, for example, on the display unit 241. The evaluation information generated in step S6 is also transmitted from the ophthalmologic apparatus 1 to an external device. The evaluation information generated in step S6 is also recorded on a recording medium. This completes the process of this operation example.

[0192] <OCTA image of a model eye> Fig. 16 shows an OCTA image obtained by an ophthalmic device according to an exemplary embodiment. Fig. 16(A) is a front view (OCTA front image) 700 of an OCTA image of a model eye provided with three liquid storage sections. The three liquid storage sections provided in this model eye have the following characteristics: the three capillaries corresponding to the three liquid storage sections have the same form (shape, length, diameter, etc.); liquids with different viscosities (relatively low viscosity liquid, relatively medium viscosity liquid, relatively high viscosity liquid) are sealed in; the three types of liquids with different viscosities have the same amount (weight percentage) of fine particles with the same form (material, size, etc.) added.

[0193] In the OCTA front image 700, three images (three pseudo blood vessel images) 701, 702, and 703 corresponding to the three liquid storage sections are depicted. The pseudo blood vessel image 701 is an image caused by the Brownian motion of particles in a relatively low-viscosity liquid (i.e., an image expressing a change in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 702 is an image caused by the Brownian motion of particles in a relatively medium-viscosity liquid (i.e., an image expressing a change in light scattering due to particles undergoing Brownian motion). The pseudo blood vessel image 703 is an image caused by the Brownian motion of particles in a relatively high-viscosity liquid (i.e., an image expressing a change in light scattering due to particles undergoing Brownian motion).

[0194] That is, the pseudo blood vessel image 701 is an image representing light scattering caused by particles moving through the liquid at a relatively high speed, and is an image of a relatively high-intensity signal. The pseudo blood vessel image 702 is an image representing light scattering caused by particles moving through the liquid at a relatively medium speed, and is an image of a relatively medium-intensity signal. The pseudo blood vessel image 703 is an image representing light scattering caused by particles moving through the liquid at a relatively low speed, and is an image of a relatively low-intensity signal.

[0195] Image 710 in Fig. 16(B) is a B-scan image taken along the longitudinal direction of the pseudo blood vessel image 701. Image 720 in Fig. 16(C) is a B-scan image taken along the longitudinal direction of the pseudo blood vessel image 702. Image 730 in Fig. 16(D) is a B-scan image taken along the longitudinal direction of the pseudo blood vessel image 703.

[0196] The B-scan image 710 includes an image (pseudo blood vessel image) 711 corresponding to the pseudo blood vessel image 701. The pseudo blood vessel image 711 is an image caused by the Brownian motion of particles in a liquid with a relatively low viscosity. In other words, the pseudo blood vessel image 711 is an image caused by particles moving in the liquid at a relatively high speed, and represents a signal with a relatively high intensity.

[0197] The B-scan image 720 includes an image (pseudo blood vessel image) 721 corresponding to the pseudo blood vessel image 702. The pseudo blood vessel image 721 is an image caused by the Brownian motion of particles in a liquid of relatively medium viscosity. In other words, the pseudo blood vessel image 721 is an image caused by particles moving in the liquid at a relatively medium speed, and represents a signal of relatively medium intensity.

[0198] The B-scan image 730 includes an image (pseudo blood vessel image) 731 corresponding to the pseudo blood vessel image 703. The pseudo blood vessel image 731 is an image caused by the Brownian motion of particles in a relatively highly viscous liquid. In other words, the pseudo blood vessel image 731 is an image caused by particles moving relatively slowly in the liquid, and represents a signal of relatively low intensity.

[0199] The intensity of a signal corresponding to a pseudo blood vessel image increases as the contrast difference (contrast ratio) between the pseudo blood vessel image and its surroundings increases, and decreases as the contrast difference (contrast ratio) decreases.

[0200] 16, by using the eye model according to the exemplary embodiment, an OCTA image similar to an OCTA image of a human fundus can be obtained. That is, it can be said that the eye model according to the exemplary embodiment has characteristics similar to those of a human fundus, at least with respect to characteristics that can be detected by OCTA.

[0201] <Method for manufacturing laminate> A laminate manufacturing method according to an exemplary embodiment will be described. Fig. 17 shows an example of a method for manufacturing a laminate in which a liquid storage section is disposed between layers. As described above, the location of the liquid storage section is not limited to this (see Figs. 9 to 12, for example). When the liquid storage section is disposed at a position other than between layers, a manufacturing method according to the location of the liquid storage section can be adopted.

[0202] 17, it is assumed that some design items of the laminate are preset, such as the number of layers, the number of liquid storage portions, and the positions of the liquid storage portions.

[0203] In addition, design items related to the liquid storage section may also be set in advance. For example, it is possible to determine in advance the form of the liquid storage section (shape, length, diameter, etc.), the material of the liquid, the viscosity of the liquid, the material of the microparticles, the amount of microparticles to be added to the liquid, etc.

[0204] Furthermore, the shape and dimensions (area, thickness, volume, etc.) of each layer may also be set in advance. The shape and dimensions of each layer do not have to be set in advance, and for example, the shape and dimensions of the layer may be determined and adjusted depending on the state of the formed layer. In this example, for each of the multiple layers included in the target laminate, the amount of base material separated in step S11-1 and the amount of fine particles separated in step S11-2 are set in advance (for example, see the amount of fine particles added described above).

[0205] In the laminate manufacturing method of this example, first, a predetermined number of liquid storage parts are created in accordance with predetermined design items (S10). The liquid storage parts are created in the manner described above (see, for example, FIG. 8).

[0206] Next, the materials for forming the first layer are weighed (S11). In this example, for the first layer, the base material is weighed (S11-1) and the fine particles to be added thereto are weighed (S11-2). As a result, a predetermined amount of the base material and a predetermined amount of the fine particles used to form the first layer are obtained.

[0207] Next, the predetermined amount of the fine particles obtained in step S11-2 is added to the predetermined amount of the base material obtained in step S11-1 (S12).

[0208] Next, the base material into which the fine particles have been added in step S12 is stirred, and degassing (degassing) is performed to remove gas dissolved in the base material (S13). Any known method can be used for stirring and degassing. This removes unnecessary gas from the base material, and disperses the fine particles in the base material.

[0209] Next, the mixture (material containing at least the base material and the fine particles) obtained in step S13 is processed into a layer (S14). Any known method can be used for this layer processing, and for example, a spin coating method can be applied.

[0210] Next, the mixture processed into layers in step S14 is hardened (S15). For example, a physical hardening method using heat or a chemical hardening method using a predetermined substance is used for this hardening process. This completes the formation of the first layer.

[0211] If the last layer of the preset number of layers was formed in the immediately preceding step S15 (S16: Yes), the target laminate is completed (end). On the other hand, if the layer formed in the immediately preceding step S15 is not the last layer of the preset number of layers (S16: No), the process proceeds to the next step S17. Note that in this example, since two or more layers are formed, the process proceeds to step S17 at this stage where only the first layer has been formed, determining "No."

[0212] If "No" is selected in step S16, one or more of the predetermined number of liquid storage units created in step S11 are placed at a predefined position on the top surface of the layer formed in the immediately preceding step S15. The process of step S17 is performed only when a liquid storage unit is placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter. In other words, if "No" is selected in step S16 and no liquid storage unit is placed between the layer formed in the immediately preceding step S15 and the layer to be formed immediately thereafter, the process of step S17 is skipped and the process proceeds to step S18. Then, steps S11 to S15 are performed again to form the next layer. Also, execution or skipping of step S17 is selected depending on the predetermined installation position of the liquid storage unit.

[0213] Steps S11 to S15 and step S17 are repeatedly executed until step S16 is judged as "Yes." That is, steps S11 to S15 are repeatedly executed the same number of times as the number of layers set in advance, together with step S17 which is executed as appropriate. This results in a laminate including one or more liquid storage sections in a preset arrangement and including a preset number of layers.

[0214] According to this laminate manufacturing method, it is possible to easily and reliably produce a laminate including a predetermined number of layers each having a predetermined characteristic and a predetermined number of simulated blood vessels. In particular, since the method is configured to harden one layer before proceeding to the formation process of the next layer, it is possible to manufacture the desired laminate with high ease and high reliability.

[0215] In addition, when the laminate contains two or more layers, the same substrate may be used for all layers, or two or more substrates may be used separately. By using the same substrate for all layers, a laminate in which all layers have the same refractive index can be obtained.

[0216] The same particles may be used for all layers, or two or more particles may be used separately.In addition, two or more layers having the same scattering properties may be formed in succession and these two or more layers may be treated as a single layer.

[0217] Although the eye model of the exemplary embodiment described above includes a laminate including a substrate and a plurality of layers, the eye model of other exemplary embodiments may not have a plurality of layers. Some examples of such eye models are described below.

[0218] 18A is a top view of a simulated fundus 800, which can be used as the fundus portion 570 of the model eye 500. The simulated fundus 800 includes a substrate 810. On the substrate 810, a liquid storage portion 830-m may have a configuration similar to that of the liquid storage portion 630-m described above. The liquid storage portion 830-m is fixed to the upper surface of the substrate 810 by fixing portions 840-1 and 840-2. The fixing portion 840-1 and 840-2 may be fixed in any manner, and may be bonded, for example, by an adhesive. In this example, a plurality of layers is not provided on the substrate 810, but this is not limited thereto.

[0219] When the ophthalmic device 1 applies a scan for OCTA to the pseudo fundus 800, the measurement light LS that passes through the approximate center of the objective lens 22 is projected onto the pseudo fundus 800. The ophthalmic device 1 detects the return light of the measurement light LS projected onto the pseudo fundus 800 to construct an OCTA image. Unlike the case where a plurality of layers 620-1, 620-2, . . . , 620-N are provided as in the laminate 600 of the above-mentioned embodiment, the pseudo fundus 800 of this embodiment does not undergo refractive index matching, and therefore very strong regular reflection occurs. In addition, regular reflection also occurs on the surface of the liquid storage section 830-m (capillary). As described above, the measurement light LS passes through the objective center and is projected from the front onto the pseudo fundus 800, so that OCTA is strongly affected by regular reflection. In other words, the return light of the measurement light LS contains a large regular reflection component. Under such a condition, it is not possible to appropriately grasp the state of Brownian motion in the liquid storage section 830-m. To solve this problem, in this embodiment, diffuse reflection is used to detect the state of Brownian motion in the liquid storage section 830-m, the operation of which will be described below with further reference to FIG.

[0220] 18A and 18B, the liquid storage section 830-m is disposed at a position away from the central region of the substrate 810. Reference numeral 850 denotes a range (observation range) to which scanning for OCTA is applied. Reference numeral 860 denotes a region onto which the measurement light LS that has passed through the objective center is projected. The projection region 860 of the measurement light LS is disposed in the central region of the substrate 810.

[0221] With this configuration, it is possible to detect the state of Brownian motion in the liquid storage unit 830-m by utilizing the diffuse reflection of the measurement light LS projected at a position outside the liquid storage unit 830-m, without projecting the measurement light LS directly onto the liquid storage unit 830-m. That is, the return light of the measurement light LS projected onto the projection area 860 includes the diffuse reflected light that has passed through the liquid storage unit 830-m among the diffuse reflected light in the projection area 860, and this embodiment can detect the state of Brownian motion in the liquid storage unit 830-m based on this diffuse reflected light.

[0222] In the pseudo fundus 800A shown in FIG. 18C, one or more liquid storage units 830A are provided in the central region of the substrate 810A. The liquid storage unit 830A is fixed to the upper surface of the substrate 810A by a fixing unit 840A. Reference numeral 850A denotes an observation range. When the pseudo fundus 800A is used for evaluating the OCTA function, the projection region 860A of the measurement light LS overlaps with the liquid storage unit 830A, so that the return light of the measurement light LS is mixed with strong regular reflection, and the state of Brownian motion in the liquid storage unit 830A cannot be suitably detected. Although it is possible to adopt such a configuration, it is preferable to additionally provide a means for preventing regular reflection. For example, it is possible to apply a coating for suppressing regular reflection to the surface of the liquid storage unit 830A and / or the upper surface of the substrate 810, to provide an optical filter for reducing or blocking regular reflection, or to perform a filter treatment for reducing or removing the regular reflection component of the return light.

[0223] FIG. 19 shows another embodiment of the pseudo fundus in which the liquid storage section is disposed at a position outside the projection area of ​​the measurement light LS. The simulated fundus 900 includes a substrate 910. On the substrate 910, M liquid storage sections 930-1, 930-2, ..., 930-M are disposed to form an M-sided polygon (M is an integer of 1 or more). The M liquid storage sections 930-1, 930-2, ..., 930-M are fixed to the upper surface of the substrate 910 by M fixing sections 940-1, 940-2, ..., 940-M. Each liquid storage section 930-m may have a configuration similar to that of the liquid storage section 630-m described above. Reference numeral 950 denotes an observation range. Reference numeral 960 denotes a projection area of ​​the measurement light LS. This embodiment also makes it possible to detect the state of Brownian motion in the liquid storage section 930-m by utilizing diffuse reflection without being affected by strong regular reflection.

[0224] <Characteristics, Function, Effects> With respect to the exemplary aspects disclosed above, some features, some operations, and some advantages will be described.

[0225] The eye model (500) of some exemplary embodiments is used in the field of ophthalmology and includes a liquid container (630-m) that contains a liquid in which particulates are suspended.

[0226] According to the model eye having such a configuration, it is possible to detect the state of Brownian motion of particles suspended in the liquid stored in the liquid storage section by OCTA. Therefore, the model eye of the exemplary embodiment can be used as a phantom for OCTA.

[0227] In addition, the model eye of the exemplary embodiment uses Brownian motion to generate an OCTA signal, and therefore does not require a liquid flow generator to mimic blood flow. Therefore, the structure of the model eye of the exemplary embodiment is simple and compact. The liquid storage unit may have a shape that mimics a blood vessel, and may include, for example, a tubular body (640) that contains a liquid to which fine particles are added.

[0228] In order to further improve the actions and effects of such exemplary embodiments and / or to obtain other actions and effects, various configurations and features described below can be optionally adopted.

[0229] The eye model (500) of some exemplary embodiments may include a plurality of liquid storage units (630-1 to 630-M). In this case, the plurality of liquid storage units (630-1 to 630-M) may store liquids of different viscosities. This configuration makes it possible to simulate a plurality of different blood flow conditions.

[0230] In some exemplary embodiments, the liquid storage units (630-1 to 630-M) may store liquids in which particles of different sizes are suspended. This configuration makes it possible to simulate a number of different blood flow conditions.

[0231] In some exemplary embodiments, at least one of the liquid storage units (630-1 to 630-M) may be arranged at an angle to the axial direction. This configuration allows the blood vessel distribution of the human fundus to be simulated. Furthermore, since it becomes possible to detect signal changes due to the Doppler effect caused by Brownian motion, it becomes possible to use the model eye of the exemplary embodiment as a phantom for evaluating the blood flow parameter measurement function.

[0232] In some exemplary embodiments, at least two of the liquid storage sections (630-1 to 630-M) may be arranged at different inclination angles with respect to the axial direction. This configuration makes it possible to simulate a number of different blood flow conditions.

[0233] The eye model 500 of some exemplary embodiments may further include a laminate 600 made up of a plurality of layers 620-1 to 620-N. Such an eye model has a structure similar to that of a human fundus, and therefore can be used as a phantom for OCT structural imaging in addition to being used as a phantom for OCTA.

[0234] The liquid storage section (630-m) in the model eye (500) of the exemplary embodiment may be disposed in any manner. For example, as shown in FIG. 10(A), the liquid storage section may be disposed inside any of the multiple layers. Also, as shown in FIG. 10(B), a liquid storage section may be provided in each of at least two of the multiple layers. Also, as shown in FIG. 10(C) and FIG. 10(D), the liquid storage section may be disposed across at least two of the multiple layers. These are presented as non-limiting examples that mimic the vascular distribution pattern in the human fundus.

[0235] In some exemplary embodiments, a part of the liquid storage unit may be exposed from the laminate. In the example shown in FIG. 11, both ends of the liquid storage unit are exposed from the laminate, but the present invention is not limited to such an embodiment. For example, a configuration in which only one end of the liquid storage unit is exposed from the laminate, or a configuration in which the center of the liquid storage unit is exposed from the laminate, may be adopted. In general, any part of the liquid storage unit may be exposed from the laminate. According to such a configuration, the liquid storage unit can be visually recognized from the outside, which can facilitate the task of placing the model eye on the ophthalmic device and the task of determining the application part of the OCT scan.

[0236] In some exemplary embodiments, a configuration that allows the orientation of the liquid storage unit to be changed can be adopted. In the example shown in FIG. 12, the liquid storage unit is configured to be rotatable in a plane perpendicular to the direction (axial direction) in which the layers of the laminate are stacked (a plane that substantially corresponds to the xy plane when the OCT scan is applied by the ophthalmic device 1), but the orientation change mode of the liquid storage unit is not limited to this. For example, the plane to which the rotational orbit of the liquid storage unit belongs is not limited to the xy plane, and may be any plane. In addition, the rotation direction of the liquid storage unit is not limited to a single direction, and may be rotation in any two modes of rotation in the xy plane, rotation in the yz plane, and rotation in the zx plane, for example.

[0237] The model eye (500) of some exemplary embodiments may further include a first temperature control unit (470) for maintaining a constant temperature of the liquid in the liquid storage unit (630-m). With such a configuration, the state of Brownian motion of particles floating in the liquid can be stabilized, and the performance as a phantom can be stabilized. This can improve the accuracy, precision, and reproducibility in the performance evaluation of the OCTA function. Note that, although the temperature control unit 470 in the example shown in FIG. 14 is expressed as an element separate from the model eye 500, at least a part of the first temperature control unit (470) may be incorporated in the model eye (500), may be attached to the model eye (500), or may be connected to the model eye (500) by wire or wirelessly.

[0238] Some exemplary embodiments of the model eye (500) may further include a second temperature control unit (470) for changing the temperature of the liquid in the liquid storage unit (630-m). With this configuration, the state of Brownian motion of particles floating in the liquid can be adjusted so as to achieve a desired function as a phantom. Note that, although the temperature control unit 470 in the example shown in FIG. 14 is expressed as an element separate from the model eye 500, at least a part of the second temperature control unit (470) may be incorporated in the model eye (500), may be attached to the model eye (500), or may be connected to the model eye (500) by wire or wirelessly.

[0239] The model eye (500) according to an exemplary embodiment may include a laminate (570; 600) according to any of the exemplary embodiments and a lens (510, 550) capable of forming a focus on the laminate.

[0240] Any of the features disclosed in the above exemplary embodiments can be combined with the model eye of the exemplary embodiment.

[0241] An ophthalmic device (1) according to an exemplary embodiment includes a data acquisition unit and a model eye. The data acquisition unit (2, 100, 210, 220; 410) has a configuration for optically acquiring data of the eye. The model eye (500) is used for evaluation of the data acquisition unit. The model eye includes a liquid storage unit (630-m) that stores a liquid in which fine particles are suspended.

[0242] By using an ophthalmic device equipped with a model eye of this configuration, it is possible to evaluate the performance of the OCTA function of this ophthalmic device by utilizing the Brownian motion of particles floating in the liquid stored in the liquid storage unit.

[0243] The ophthalmic device (1) of some exemplary embodiments may further include an evaluation unit (440). The evaluation unit is configured to generate evaluation information based on data acquired from the eye model by the data acquisition unit.

[0244] According to this aspect, since the ophthalmologic apparatus can perform performance evaluation by itself, it is possible to easily perform adjustment and calibration after installation in, for example, a medical institution. In addition, by configuring the apparatus to automatically perform periodic quality evaluation and transmit the evaluation results to a maintenance server, it becomes possible to provide a remote maintenance service. The method of using the evaluation results is not limited to the above.

[0245] In some exemplary embodiments of the ophthalmic device (1), the data acquisition unit may include an optical system (2, 100; 410). The ophthalmic device may further include an alignment system (420, 420A, 420B). The alignment system is configured to align the optical system with a model eye (500) placed at a predetermined position. In addition, the evaluation unit (440) may be configured to generate evaluation information based on data acquired from the model eye by the data acquisition unit after the alignment.

[0246] According to this aspect, it is possible to facilitate the evaluation of an ophthalmic device using a model eye. That is, in order to properly perform an evaluation using the model eye, it is necessary to accurately position the model eye with respect to the optical system of the ophthalmic device to be evaluated, but the ophthalmic device of this aspect does not require the cumbersome task of manually adjusting the position of the model eye.

[0247] According to the present aspect, the ophthalmic device can be evaluated with the model eye placed in a suitable alignment state. Therefore, the ophthalmic device can be appropriately evaluated. For example, according to the present aspect, it is possible to improve the accuracy, precision, and reproducibility of the evaluation of the ophthalmic device.

[0248] Furthermore, according to this aspect, it is possible to evaluate not only the imaging performance and measurement performance of the ophthalmic apparatus, but also the alignment performance.

[0249] In some exemplary embodiments of the ophthalmic device (1), the data acquisition unit (2, 100, 210, 220; 410) can acquire data from a specific portion of the model eye (500) at least twice. Furthermore, the evaluation unit (440) can generate evaluation information based on two or more pieces of data acquired from the specific portion of the model eye by the data acquisition unit. By employing this configuration, it becomes possible for the ophthalmic device itself to evaluate the performance of the OCTA function.

[0250] Any of the features disclosed in the above exemplary embodiments may be combined with the ophthalmic apparatus of the exemplary embodiment.

[0251] The above disclosure is merely an example of the implementation of the present invention. Those who intend to implement the present invention can make any modifications (omissions, substitutions, additions, etc.) within the scope of the gist of the present invention. [Explanation of symbols]

[0252] 1 Ophthalmology equipment 500 model eyes 630-m (m=1,...,M; M is an integer of 1 or more) Liquid storage section

Claims

1. A model eye for use in the field of ophthalmology, A liquid storage section in which a liquid in which particles undergoing Brownian motion are suspended is sealed and stored, Model eyes.

2. A plurality of said liquid storage units are included. The eye model of claim 1.

3. The liquids having different viscosities are stored in the liquid storage units. The eye model of claim 2.

4. The liquids in which the particles of different sizes are suspended are stored in the liquid storage units. The eye model according to claim 2 or 3.

5. a data acquisition unit that acquires eye data using optical coherence tomography angiography; A model eye to which optical coherence tomography angiography is applied for evaluation of the data acquisition unit; An ophthalmic device comprising: The model eye includes a liquid storage section in which a liquid in which particles performing Brownian motion are suspended is sealed and stored. Ophthalmology equipment.

6. The data acquisition unit applies optical coherence tomography angiography to the model eye to generate a pseudo blood vessel image which is an image representing a change in light scattering caused by the particles performing the Brownian motion; and an evaluation unit that generates evaluation information based on the simulated blood vessel image. The ophthalmic device of claim 5.

Images